What Is the Outside of a Car Made Of?

The outside of most cars is primarily made from steel or aluminum body panels coated in paint, with plastic bumper covers and exterior trim; some vehicles add composite panels (like fiberglass or carbon fiber), and a few use stainless steel skins. In practice, automakers mix materials to balance cost, weight, safety, durability, and repairability.

The main materials that form a car’s exterior

Steel: the long-time staple

Steel remains the most common exterior material, especially in mass-market sedans, crossovers, and many SUVs. Modern cars often use galvanized or galvannealed sheet steel for corrosion resistance, along with advanced high-strength steels (AHSS and UHSS) that allow thinner panels without sacrificing structural integrity. Many outer panels—doors, roofs, fenders, and quarter panels—are stamped from steel and spot-welded to the body-in-white.

Aluminum: light and increasingly common

Aluminum reduces weight, improving efficiency and handling. Automakers use it for hoods, trunk lids, doors, and sometimes entire bodies. The Ford F‑150 (since 2015) features an aluminum body over a steel frame; Land Rover and Jaguar SUVs lean heavily on aluminum, and Tesla’s Model S/X bodies are predominantly aluminum. Aluminum panels are typically bonded, riveted, or spot-welded with specialized processes and receive conversion coatings before paint to resist corrosion.

Plastics and polymers: the visible “soft” exterior

While the structural surface is metal, the most impact-prone pieces you see and touch—bumper covers, rocker claddings, wheel-arch trims, mirror housings, grilles, and some hatch or spoiler pieces—are plastics. Common formulations include polypropylene (PP) and thermoplastic olefin (TPO) for bumper skins, ABS for trim, polycarbonate (PC) for headlamp lenses, acrylic (PMMA) for light covers, and nylon blends for grilles. These parts are paintable, flexible, and resist minor impacts; a metal or high-strength beam sits behind bumper covers to absorb crashes.

Composites: from specialty to mainstream niches

Composite body panels show up where low weight, complex shapes, or dent resistance are priorities. Sheet molding compound (SMC, a fiberglass-reinforced thermoset) is widely used in vehicles like the Chevrolet Corvette. Carbon-fiber-reinforced polymer (CFRP) appears on higher-performance or premium models for roofs, hoods, and trunk lids (e.g., BMW M models) and was used extensively on the BMW i3. These parts are light and stiff but costlier and more specialized to repair.

Stainless steel: a notable exception

Although rare due to cost, weight, and forming challenges, stainless steel has re-emerged in the Tesla Cybertruck, which uses thick cold-rolled stainless exterior panels. Historically, the DeLorean DMC‑12 also used unpainted stainless steel skins. This choice prioritizes durability and a distinctive appearance over easy dent repair.

Glass: part of the exterior envelope

Windows and panoramic roofs contribute to the exterior. Windshields are laminated safety glass; side and rear windows are typically tempered glass. Many modern vehicles feature large glass roofs that change the visual “skin” of the car and affect weight distribution and body stiffness.

How a modern car’s “skin” is built

Automakers first assemble the body-in-white—the welded, bonded shell of structural and exterior panels—then add closures (hood, doors, trunk/tailgate) and plastic fascias and trim. Bumper systems pair a plastic cover with an energy-absorbing foam and a steel or aluminum reinforcement beam, mounted to crash structures. Roofs may be steel, aluminum, composite, or large glass panels.

Paint and coatings

The visible finish is a multilayer system designed for corrosion protection and appearance: an electrocoat (e-coat) primer coats the metal shell, followed by primer-surfacer, colored basecoat, and a hard clearcoat. Galvanized steel resists rust, while aluminum receives conversion coatings for paint adhesion. Optional paint-protection films (PPF) and ceramic coatings add chip and scratch resistance after purchase.

Material choices by vehicle type: common patterns and examples

Different segments adopt different exterior materials to hit targets for cost, weight, durability, and performance. Below are typical trends seen in recent models.

• Mass-market sedans and crossovers: Mostly steel (including AHSS) for body panels; aluminum often used for hoods or trunk lids to save weight.
• Pickup trucks and traditional SUVs: Predominantly steel bodies; the Ford F‑150 shifted to an aluminum body, while many rivals remain steel-centric.
• Luxury and off-road SUVs: Frequent aluminum use to offset size and features; Land Rover and Jaguar emphasize aluminum bodies and closures.
• EVs: Mixed-material strategies for range and crash safety—Tesla Model 3/Y blend steel and aluminum; Model S/X lean aluminum; Rivian uses mixed metals and composites.
• Sports and supercars: Composites and aluminum are common—Corvette uses SMC composites for body panels; McLaren and many exotics use CFRP panels; BMW M models often feature carbon-fiber roofs.
• Outliers: Tesla Cybertruck’s cold-rolled stainless steel exterior; classic DeLorean’s unpainted stainless panels.

These choices reflect engineering trade-offs: steel keeps costs down and repairs straightforward; aluminum and composites cut mass; stainless delivers durability and a unique look at the expense of easy formability and dent repair.

Material trade-offs that shape the exterior

Automakers weigh several factors when deciding what the “outside” is made of. Here’s how the materials compare across key criteria.

• Weight: Aluminum and composites are lighter than steel; lower mass improves efficiency and handling.
• Cost: Steel is cheapest; aluminum costs more; CFRP is the most expensive; plastics are economical for complex shapes.
• Strength and crash: AHSS/UHSS offer high strength; aluminum can achieve strong structures with proper design; composites excel in stiffness-to-weight but behave differently in crashes.
• Corrosion: Galvanized steel resists rust; aluminum naturally resists corrosion; stainless is highly corrosion-resistant; plastics and composites don’t corrode.
• Repairability: Steel is widely repairable; aluminum needs specialized tools; composites require specialized techniques; stainless can be difficult to reform or finish-match.
• Manufacturing: Steel stamping and spot welding are mature and efficient; aluminum often uses bonding/riveting; composites allow complex shapes with different cycle times.

No single material wins on every metric; that’s why most modern vehicles combine several to meet performance and price targets.

Typical exterior parts and their materials

While every model differs, many exterior components follow consistent material choices across brands.

• Hood, roof, doors, fenders, quarter panels: Steel or aluminum; composites on some performance or specialty models.
• Bumper covers and cladding: TPO/PP plastics; behind them, aluminum or high-strength steel reinforcement beams with foam energy absorbers.
• Tailgates and liftgates: Steel or aluminum; some use plastic/composite outer skins.
• Headlamp lenses and light covers: Polycarbonate or acrylic with hardcoats for UV and abrasion resistance.
• Grilles, mirror housings, spoilers, trim: ABS, PP, or painted/plated plastics; some premium trims use metal or composite accents.
• Wheel-arch liners, underbody shields, splash guards: HDPE, PP, or fiber-reinforced plastics for impact and corrosion resistance.
• Roofs: Steel or aluminum; optional carbon-fiber panels on performance models; large panoramic glass roofs on many modern vehicles.

These conventions balance durability in high-impact areas with aesthetics and manufacturing practicality for visible surfaces.

Trends and sustainability

Material strategies are evolving. Automakers increasingly use closed-loop aluminum recycling, higher-strength steels to reduce thickness, and recycled plastics for non-structural parts. Composite adoption is spreading for specific panels where weight or dent resistance matter. Large glass roofs and advanced coatings are changing exterior design and maintenance. Regulations and consumer demand for efficiency and lower lifecycle emissions continue to push mixed-material bodies and improved corrosion protection.

Summary

The exterior of a car is typically a mix: steel or aluminum for the main body panels, plastic for bumper covers and trim, selective composites for specialty parts, and glass for windows and roofs—topped with multilayer paint and clearcoat. Choices vary by segment and brand: steel offers affordability and easy repairs; aluminum and composites cut weight; stainless steel appears in rare cases. Most modern vehicles combine these materials to meet performance, safety, cost, and sustainability goals.

What are car bodies made of today?

Car bodies today are most commonly made of steel and aluminum, with steel remaining a cost-effective choice for mass-produced vehicles. Aluminum is increasingly used for its lightweight properties, which improve fuel efficiency, particularly in larger vehicles. For higher-performance or more expensive sports cars, bodies can be made from strong but costly carbon fiber. Additionally, lightweight magnesium alloys are used for specific components, and various types of plastic are used for other parts like front and rear panels. 
Key materials and their uses:

• Steel: Opens in new tabRemains the traditional and most widely used material due to its strength, durability, and low cost. 
• Aluminum: Opens in new tabBecoming the material of choice for its lighter weight and corrosion resistance, used in components like hoods and liftgates. 
• Carbon Fiber: Opens in new tabA very strong and lightweight material, but its high cost restricts its use to high-end or specialty vehicles. 
• Plastic: Opens in new tabUsed extensively for various parts, including front and rear panels and other trims. 
• Magnesium Alloys: Opens in new tabLightweight magnesium is increasingly used for certain body components. 

Why the different materials are chosen:

• Cost: Steel is the most economical choice for most vehicles. 
• Weight: Aluminum and carbon fiber help reduce vehicle weight, leading to better fuel efficiency and performance. 
• Strength and Safety: All materials are chosen to meet strict safety standards, with different steels and other materials providing varying levels of crash protection. 
• Corrosion Resistance: Aluminum and certain steel treatments are important for protecting against rust. 

What is the exterior of a car made of?

Car exteriors are primarily made of steel, but modern vehicles also incorporate aluminum, plastic, and carbon fiber to balance weight, strength, and cost. Steel is a traditional choice for its strength and affordability, while aluminum offers a lighter, rust-resistant alternative. Plastic is common for non-structural parts like bumpers, and carbon fiber is a high-tech, expensive option for lightweighting performance vehicles.
 
Main Exterior Materials

• Steel: Opens in new tabThe most common and traditional material, steel provides excellent strength and collision resistance at a lower cost, making it ideal for the structural chassis and body panels of mass-produced vehicles. 
• Aluminum: Opens in new tabUsed in luxury and performance cars, aluminum is significantly lighter than steel and resistant to rust, which helps improve fuel efficiency and performance, according to Quora users. 
• Plastic: Opens in new tabFound in non-structural components such as bumpers, door handles, and trim, plastic is chosen for its light weight, flexibility, and ability to be molded into complex shapes. 
• Carbon Fiber: Opens in new tabA high-end material used in supercars and advanced models, carbon fiber is exceptionally strong and very lightweight, contributing to improved performance and reduced overall vehicle mass. 

Other Materials 

• Glass: Used for windows and windshields.
• Paint and Clear Coat: The outermost layers that provide protection and a finished appearance.
• Rubber: Used for seals, weather stripping, and other components.

Is the outside of a car plastic?

Plastic and rubber can be found all over a car’s exterior — the trim, molding, bumpers, even the brackets that hold wiper blades.

What is the outside of a car called?

The outside of a car is called its body or body shell, which are the outer metal or plastic panels that form its shape and protect the interior and mechanical components. This “skin” of the car includes parts like doors, the hood, trunk, roof, fenders, bumpers, and windows.
 
Key terms for the outside of a car:

• Body: The most common term for the entire external structure and panels of the car. 
• Body Shell: This refers to the outer layer of the car’s structure that wraps around the interior and mechanical components. 
• Panels: These are the individual metal or plastic coverings, such as doors, fenders, and the hood, that make up the body shell. 

Examples of exterior parts: 

• Doors: Allow entry and exit.
• Hood (or Bonnet): Covers the engine compartment.
• Trunk (or Boot): The rear storage compartment.
• Roof: Protects passengers from the elements.
• Fenders: Curved parts over the wheels that prevent debris from splashing.
• Bumpers: Located at the front and rear to absorb impact during low-speed collisions.
• Windows/Windshield: Provide visibility for the driver and passengers.