The fact that movies prefer to show a big dramatic explosion in a fictional context does not mean that cars can't catch fire in real life.

http://www.usfa.fema.gov/statistics/reports/vehicles.shtm

Sure -- but a small percentage of them does it in a crash.

Of course, if you are so inclined (either way), you can explain away any coincidence.

We had the "conspiracy theorists", not we have the "coincidence theorists".

Cars can catch fire in real life: http://www.liveleak.com/view?i=54e_1333912420

See also: Ryan Dunn's 911, post-tree.

Hollywood may exaggerate the rate at which that happens, but not much more.

Ryan Dunn was driving at 130mph when he hit that tree. Not a great example for your position...

What makes you think his case sets a lower bound on the speed required to start a fire?

Physicists tend to like to repeat an experiment lots of times before attempting to make conclusions based on empirical observations.

Given the distance the drive train was tossed in this wreck, I don't think there was any shortage of kinetic energy being dissipated into the vehicle.