The 2010-ish model Jeeps had a habit of doing exactly that. Here's a video showing a bunch of similar catastrophic fires in Jeep Wranglers occurring without any sort of collision. And of course Chrysler's special investigators almost always just hand waved away the defects as not their problem and not a defect with the vehicle.

https://www.youtube.com/watch?v=iyEaC9xcYhE

Vehicle fires unrelated to a crash are not unheard of for traditional gas powered cars.