When a car falls a good distance, well enough to destroy it and kill the occupants, it always have to explode into flames.
I've handled insurance auto claims for many years and in all that time, I've never seen or even heard of one of them blowing up. I've handled any kind of thing that can happen with a car (even had one fall out of a cargo plane in flight) and not one ever blew up.
I get that it's for a sense of finality as characters walk away from things that would kill anyone, but it annoys me. Just saw it last night on "Twister" where the bad guy's ride get sucked up into a twister, tossing the vehicle dozens of feet into the air, and comes down to explode in flames. The fall alone would have killed him for sure.