GM Roof Rail Lawsuit: Key Cases, Documents, and Defenses

The GM roof crush lawsuits are a decades-long line of product liability cases alleging that General Motors designed the roofs of certain trucks, SUVs, and passenger cars too weak to protect occupants in rollover crashes. Plaintiffs won multimillion-dollar verdicts, forced GM to unseal internal engineering records the company had kept confidential for years, and helped push federal regulators to double the roof strength standard for passenger vehicles sold in the United States.

What Plaintiffs Alleged

The core claim was narrow and consistent across cases. When a GM vehicle rolled over, the roof caved inward far enough to cause catastrophic injuries, typically spinal cord damage leading to paralysis or death, that a stronger roof would have prevented. Plaintiffs did not argue GM caused the rollover. They argued the design made the injuries worse than they had to be.

That theory has a name in product liability law: crashworthiness. An automaker is liable not for the initial crash but for the “second collision,” the enhancement of injuries caused by a defective design. The Nebraska Supreme Court, ruling in one of the flagship GM cases, held that a plaintiff’s role in causing the initial crash is legally irrelevant to a crashworthiness claim.¹

The vehicles most often named were the S-10 Blazer line and GM’s full-size pickup trucks, though the litigation also reached the Astro Van, Tahoe, Suburban, Malibu, Cavalier, Lumina, GMC Jimmy, Safari, Envoy, Sierra, and various Oldsmobile and Pontiac models.

The Cases That Shaped the Litigation

Lambert v. General Motors

Robbie Lambert, eighteen years old, was paralyzed in July 1990 when a Chevy S-10 Blazer rolled over in San Bernardino County, California. A Victorville jury awarded him more than $15 million in 1992, then halved the amount after finding him 50% responsible. GM appealed. An appellate court ordered a new trial, citing inconsistency in the verdict.

At retrial in 2001, a second jury returned a $25.7 million judgment, this time assigning Lambert 40% responsibility. A California appeals court affirmed the $25.7 million award on January 14, 2003, closing out GM’s challenges.²

Shipler v. General Motors

Penny Shipler was left a quadriplegic in a 1997 rollover of a 1996 Chevrolet S-10 Blazer in Nebraska. She sued GM for defective roof design and sued the driver for negligence. In 2003 the jury awarded $19,562,000, later adjusted by the court to $18,583,900.¹

The trial produced the single most damaging courtroom moment in the history of this litigation. GM’s chief liability witness, Garry Bahling, conceded under cross-examination that the conclusions in GM’s published “Malibu 2” study, which the company had relied on for years to argue that roof strength did not affect injury severity, were contradicted by GM’s own internal test data.³

The Nebraska Supreme Court affirmed on March 10, 2006, and held that contributory negligence is not a defense to a crashworthiness claim. Evidence of Shipler’s alcohol consumption and seatbelt use was properly excluded because it went to the initial crash, not the second collision.¹

Pertile v. General Motors

Pertile, filed in the U.S. District Court for the District of Colorado, involved a 2011 Chevrolet Silverado 2500HD crew cab. GM’s senior engineering group manager cited a 2005 internal evaluation claiming the GMT900 crew cab pickup exceeded federal roof strength requirements. Plaintiffs sought GM’s finite element modeling files, the computerized simulations behind those claims, to test the company’s numbers and cross-examine its expert. Magistrate Judge Nina Y. Wang and District Judge William J. Martínez ordered GM to produce the modeling data, finding the expert had “considered” the materials. As of August 2017, court records reflected GM had not yet complied.⁴

What GM’s Internal Documents Showed

The verdicts drew headlines. The documents pulled loose during discovery are what changed the trajectory of the issue.

In 1966, GM’s director of automotive safety engineering, L.C. Lundstrom, wrote in an internal letter that the company was “presently in trouble” with the A-pillar design and that retaining the windshield was “advantageous” for roof strength in rollovers. Testing in 1990 on 1992 S/T truck models showed that removing the windshield reduced roof strength by 36%, meaning the roof structure relied heavily on the glass to meet the federal standard.³

GM’s own March 1971 product test reports showed multiple production vehicles, including the 1971 Chevrolet B-47, Chevrolet H-11, and 1970 Pontiac F-87, failing to meet the roof intrusion standard then proposed at the federal level. In the early 1980s, engineer Ivars Arums documented “lateral roof crush” simulations at 45-degree angles, more realistic than the federal test, and produced roughly 33% lower strength results than the federal method. Twenty-six pages of Arums’s data and conclusions were later found missing from GM’s files.³

The “Malibu” research was the most consequential. During the 1980s, GM ran rollover tests on Chevrolet Malibu sedans and produced film, data, and analysis showing that stronger roofs resulted in less severe injuries to belted passengers. GM then published two SAE papers, “Malibu 1” in 1985 and “Malibu 2” in 1990, that it used as its primary courtroom defense, arguing roof strength had no causal relationship to injury severity. The published papers selectively presented the underlying data, and the Shipler cross-examination brought that gap into open court.⁵

How the Records Went Public

For most of the litigation’s history, GM kept its engineering records sealed under protective orders. That changed in 2004. Attorney Garo Mardirossian moved in Los Angeles Superior Court to lift the protective order in Duan v. General Motors (Case No. BC229926), a case arising from the 1999 death of Bing Lin Duan in a Chevy Aerostar van rollover. Mardirossian argued the documents were 15 to 40 years old, held no remaining commercial value, and were of “paramount importance to the health and safety of the public.” Judge Mel Red Recana granted the motion.⁵

Much of the sustained work to get the records public came from Paula Lawlor, a former researcher for trial attorney Michael Piuze who had studied GM’s internal documents beginning in 2000. She volunteered for the Center for Auto Safety, self-published a 2007 study titled “Deadly by Design,” and in 2006 hand-delivered more than 1,000 pages of GM’s internal records to a clerk at the National Highway Traffic Safety Administration, pressing the agency to strengthen the roof crush rule.⁵

GM’s Defenses and How Plaintiffs Answered

GM ran two principal defenses. The first was the Malibu research, offered to argue that roof strength did not correlate with injury severity. The second was the “diving to the roof” theory: occupants were not injured by the roof coming down on them, but by being thrown upward into the roof during a rollover. If that were true, a stronger roof would not help and might make injuries worse.

Plaintiffs’ attorneys answered with instrumented crash test data showing that dummy neck loads occurred after the roof began to crush, not before, indicating the roof was moving down onto occupants. The Shipler testimony, in which GM’s own witness acknowledged that internal data contradicted the company’s published conclusions, undercut the Malibu-based half of the defense in ways later cases could cite.⁶

The Federal Rule the Litigation Helped Change

Federal Motor Vehicle Safety Standard 216, effective September 1, 1973, required a roof to withstand a force equal to 1.5 times the vehicle’s unloaded weight (capped at 5,000 pounds) with no more than five inches of intrusion, and the test was applied to only one side of the roof. Critics, drawing on the unsealed documents, argued the standard had been shaped in the early 1970s to accommodate the vehicles automakers were already building, including successful opposition to a two-sided test.³

Congress directed a rewrite in the August 2005 SAFETEA-LU act. A June 2008 Senate subcommittee hearing pointed to the wide spread among existing vehicles, with the Volvo XC90 hitting a strength-to-weight ratio of 4.6 while the Jeep Grand Cherokee reached only 2.3, and criticized NHTSA for proposing a jump only to 2.5.⁷

NHTSA finalized FMVSS 216a on April 30, 2009. The rule doubled the strength-to-weight ratio from 1.5 to 3.0 for passenger vehicles weighing 6,000 pounds or less, required testing on both sides of the roof, extended coverage to vehicles weighing 6,000 to 10,000 pounds at a 1.5 ratio, and added headroom criteria to preserve survival space. NHTSA estimated the upgrade would prevent 135 deaths and more than 1,000 nonfatal injuries each year, with full compliance required by model year 2016.⁸

A 2020 NHTSA study later found that raising a vehicle’s peak strength-to-weight ratio by one unit reduced the odds of a non-ejected occupant suffering a severe rollover injury by approximately 14%.⁹ In May 2025, NHTSA proposed removing the original FMVSS 216 as obsolete now that FMVSS 216a is fully in force, and finalized the removal with an effective date of July 6, 2026.¹⁰

A Note on GM’s Roof Rail Airbag Recalls

If you are searching this topic because of a GM airbag recall notice, that is a different issue. Recent recalls of the 2014 Chevrolet Cruze, Buick Verano, and 2015–2016 Silverado and Sierra pickups involve manufacturing defects in the roof rail airbag inflators, hardware housed above the headliner that can rupture and send fragments into the cabin. Those recalls concern the airbag components themselves, not the structural strength of the roof at issue in the crush litigation.¹¹

1
FindLaw. Shipler v. General Motors Corporation
2
Los Angeles Times. Court Affirms Lambert v. GM Verdict
3
Public Citizen. GM Roof Crush Documents From Litigation
4
eDiscovery Law. Pertile v. General Motors LLC, Case Opinion
5
Reuters. Special Report: USA Courts Secrecy
6
Regulations.gov. Michael Piuze Roof Crush Litigation Record
7
GovInfo. Senate Subcommittee Hearing on Roof Crush Standards
8
NHTSA. FMVSS 216a Final Rule
9
NHTSA. Roof Crush Resistance and Rollover Injury Outcomes
10
Federal Register. FMVSS No. 216 Removal, Final Rule
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NHTSA. NHTSA Recall 23V674, Chevy Cruze and Buick Verano