I would run away and call for help on my mobile. No way am I going near that potentially exploding car for numerous reasons, for one thing I don't care about strangers. I value my life more than someone I don't know...Hell I value my life more than anyone I do know! I aint going near that car if it's gonna blow up in my face. I would certainly call for help cuz if I don't call and that person died in a fiery explosion then I could get done in court for not helping...Im not 100% on the laws in England for these kind of things but I think you can get sent to court if you don't help someone in need like that.