Carmageddon is an awesome game. Many happy memories.
Seem to remember the Cops (and indeed the super cop car you could actually unlock once you reached rank 12 or 9 or so) could actually be killed by using one of the heavier vehicles (The one with the hook was good), luring the Enforcer up onto a rooftop, and with a clever bit of driving, catch him head on, push him over the edge, keep in contact with him all the way down (not easy but definitely possible), and upon impact with the ground you'd both get wrecked. Luckily you could repair, and the Enforcer car would be added to your vehicles.
The best fun was reaching the top rank, unlocking all the cheat upgrades and all the cars, and taking that car with the permanent Electro-Bastard Ray attached.
Anyway, here's my new review... The Crystal Maze - The best reason in the world to watch channel 46 on Freeview