The wrongful death and negligence lawsuit was filed Monday in Los Angeles by Kristine Rodas, the wife of Walker's friend and business partner Roger Rodas.
The lawsuit against Porsche Cars North America claims the company's 2005 Porsche Carrera GT suffered from design flaws and had a malfunctioning suspension that caused the November crash and both men's deaths.
Authorities have cited unsafe speed as a cause of the crash. But Kristine Rodas' complaint says her husband was driving the Porsche at 55 mph before the accident.
An email message sent to Porsche seeking comment was not immediately returned.