Crews were called to an early morning car blaze in Preston, say fire services.
Firefighters arrived at the incident to find a white Mercedes well alight on Larkhill Street at around 3am on 7 March.
Crews extinguished the flames using a hose-reel jet.
A spokesman for Lancashire Fire and Rescue said: "We were called to a vehicle fire in Preston this morning. We do not believe it was started deliberately, however, the cause is still under investigation.
"The car was extensively flame damaged during the incident."
Nobody was injured.