In a review of lawsuits filed around the country involving a wide range of complaints — not just the sudden acceleration problems that have led to millions of Toyotas being recalled — the automaker has hidden the existence of tests that would be harmful to its legal position and claimed key material was difficult to get at its headquarters in Japan. It has withheld potentially damaging documents and refused to release data stored electronically in its vehicles.

For example, in a Colorado product liability lawsuit filed by a man whose young daughter was killed in a 4Runner rollover crash, Toyota withheld documents about internal roof strength tests despite a federal judge's order that such information be produced, according to court records. The attorneys for Jon Kurylowicz now say such documents might have changed the outcome of the case, which ended in a 2005 jury verdict for Toyota.