I've known petrol engined cars to burn, just sitting on the drive, Fords used to do this frequently. Just remember, out of all the cars Tesla has made i think 14 have burnt out due to batteries. We had a petrol engined ute burn out here this week, a 22 year old was killed and it was just parked on the side of the road. Any vehicle using any form of combustible material will occasionally malfunction.