The mod Furdle has just causes vehicles to explode if they hit anything at faster-than-crawling speeds.
I'd rather make vehicles that actually work properly than have every vehicle be a pinto. I've never seen two Jeeps colliding cause either to go into low Slate orbit, or two Tanks colliding, or two Stunt Planes, or two Turismos - or any combination of the above.
Maybe it's not just the physics engine. Maybe, just maybe, the vehicles we're making for it should hold some of the blame as well.