Interstate '76 is still the best. Never liked any other car combat games, because they were either over the top or just didn't had the same kind of "real" feeling that Interstate '76 gave me.
It makes me mad how we probably won't ever get some sort of HD remake of that game. New light engine, better shadows, better terrain graphics, more detailed cars, particle effects for dust when going off the road... that's all I need, really. Everything else can remain as is. Well, ok, maybe higher resolution cutscenes too.