I was a huge fan of Carmageddon 1. My computer couldn't really handle 2. Played the demo for awhile and I have to agree with street, that game had some of the neatest physics. The Electoro-Bastard Ray was a lot of fun too! But I degress.
One of the neatest features and innovations at the time was breakaway parts, and dynamically damaged vehicals. You could damage your bumper, make a really tight turn that broke off the bumper, and use it as a weapon to kill more peds.
It was tremendously fun to get up onto the tops of some of the buildings, and then jump off to see what kind of damage you could cause. Carmagedon 2 was really advanced, and I've seen few other games approach the realisim of that physics engine. One of the best racing games ever for that reason. Even if there wasn't a lot a "racing" that was done.