When did cars stop being made of metal?

They haven’t. Most cars today are still primarily made of metal—mainly steel, with growing use of aluminum—while plastics and composites supplement non-structural parts and, in a few cases, select panels. Over the past decades, automakers have diversified materials to save weight, improve safety, and reduce costs, but the structural backbone of mass-market vehicles remains metal.

What actually changed—and when

Early automobiles often used wood frameworks with steel panels. By the 1930s, all‑steel bodies had become the mass‑production norm, thanks to advances in stamping and welding. From the 1970s onward, plastics and composites took over many external trim pieces (especially bumpers and fascias) and interior components, driven by safety rules, rust resistance, and styling flexibility. Aluminum began replacing steel in certain panels and even full bodies in the 1990s and 2000s to reduce weight; the trend accelerated in the 2010s with aluminum-intensive vehicles and, more recently, large aluminum castings in some EVs. Carbon-fiber composites, while common in racing and supercars, remain niche in everyday cars due to cost, manufacturing speed, and repairability limits. The upshot: mainstream vehicles still rely on metal for structural integrity, with plastics and composites used strategically.

A concise timeline of materials in car bodies

The following timeline highlights major shifts in automotive body materials, showing how metal remained central even as plastics and composites appeared.

• 1900s–1920s: Wood body frameworks with steel or aluminum panels are common; metal content rises rapidly as production scales.
• 1930s: All‑steel, welded bodies become the mainstream standard in mass production, replacing wood structures.
• 1950s: Composites debut in niche models—most famously the 1953 Chevrolet Corvette’s fiberglass body panels—while the wider market stays steel.
• 1970s–1980s: Plastic bumper fascias and exterior trim proliferate; some cars adopt composite or plastic outer panels over metal frames.
• 1990s: Aluminum panels and spaceframes arrive in premium models (e.g., Audi), while brands like Saturn use polymer panels on steel spaceframes.
• 2000s–2010s: Aluminum-intensive bodies expand (e.g., Jaguar, Ford F‑150’s aluminum body panels); carbon-fiber passenger cells arrive in niche EVs (BMW i3, 2013).
• 2020s: Mixed-material platforms dominate; EVs increasingly use large aluminum castings and aluminum battery enclosures, while advanced high‑strength steel remains the structural mainstay.

Taken together, these milestones show evolution rather than replacement: metals remain fundamental, with other materials layered on for specific benefits.

What parts are metal vs. non‑metal today

Modern vehicles blend materials. Here’s a practical look at what’s typically metal and what isn’t in contemporary mass-market cars.

• Primarily metal: The body‑in‑white (structural shell), crash structures, pillars, roof rails, floorpans, subframes, and frames are mostly steel, increasingly in advanced high‑strength grades; closures (hoods, doors, trunk/hatch) are steel or aluminum; many EV battery enclosures are aluminum or steel.
• Commonly non‑metal: Bumper covers/fascias, many exterior trim pieces, underbody aero shields, wheel‑arch liners, interior panels and dashboards, and often fuel tanks (in ICE vehicles) use plastics or composites; select body panels on niche models may be fiberglass, polymer, or carbon fiber.

By weight, a typical modern car is still majority metal—often 50–65% steel plus 10–15% aluminum—while plastics and composites usually account for roughly 8–12% (higher by volume because they’re lighter).

Why automakers added plastics and composites

Plastics and composites offer corrosion resistance, styling freedom, weight savings, impact resilience for low‑speed bumps, and cost advantages for complex shapes. However, metals retain clear advantages for structural parts: predictable crash behavior, high stiffness and strength, established manufacturing speed and repair networks, and mature recycling streams. Carbon fiber adds exceptional stiffness-to-weight but remains costly and slower to produce at high volumes.

Notable exceptions that used mostly non‑metal skins

Some vehicles are known for non‑metal body panels or structures, though most still rely on metal somewhere in the core structure.

• Chevrolet Corvette (1953–present): Fiberglass/composite body panels over metal or composite structures, with extensive aluminum in modern generations.
• Pontiac Fiero (1984–1988): Plastic body panels mounted on a steel spaceframe.
• Saturn S‑Series (1990–2002): Polymer body panels on a steel spaceframe to resist dents and corrosion.
• Smart Fortwo (1998–present): Interchangeable plastic panels over a steel safety cell.
• BMW i3 (2013–2022): Carbon‑fiber‑reinforced plastic passenger cell with an aluminum chassis; exterior panels are plastic.
• Supercars (various): Carbon‑fiber monocoques with composite bodywork, prioritizing performance over cost.
• Audi A8 (from 1994): Aluminum spaceframe and panels—still metal, just lighter than steel.
• Ford F‑150 (from 2015): Aluminum body panels on a steel frame—again, metal, but a different mix.

Even in these cases, outright elimination of metal is rare; most road cars keep metal for frames or key structural elements.

Bottom line

Cars never “stopped” being made of metal. Instead, manufacturers diversified materials: plastics and composites became common for non‑structural parts starting in the 1970s, aluminum gained ground for panels and structures from the 1990s onward, and carbon fiber remains a high‑end niche. For the foreseeable future, the structural heart of mainstream vehicles will continue to be metal—primarily steel, with strategic aluminum.

Summary

There is no single date when cars ceased to be metal, because they haven’t. By the 1930s, all‑steel bodies were standard; from the 1970s onward, plastics and composites spread to trims and selected panels, and aluminum expanded to save weight. Today’s cars are mixed‑material, but structurally they are still predominantly metal.

Why did cars go from metal to plastic?

Parts are made of plastic for 2 reasons. (1) weight savings and therefor fuel savings. More attractive to consumers and govt compliance. (2) lower costs = lower sale price. Look at new car prices over time – they stay relatively affordable when you consider inflation.

What year did cars stop rusting?

Revised cathodic automotive electrocoat primer systems were introduced in the 1970s that markedly reduced the problem of corrosion that had been experienced by a vast number of automobiles in the first seven decades of automobile manufacturing.

When did cars become plastic?

In 1941, Henry Ford tried to manufacture a car entirely out of plastics. It took another ten years to reach serial production. Since the production of the Ford Model T in 1951, plastic has been found in cars all over the world. Besides metals, plastics are a widely used material in cars.

Why are cars not made out of steel anymore?

The parts that provide safety or structural support are generally metal (and most of the bodywork too, really), but there’s no need for the exterior panels to be metal. It adds to the damage done in a crash and adds unnecessary weight to the vehicle compared to other plastics/carbon fibre etc.