Over there you can even run 1:8th scale buggies with onroad tires, lowered and revised for on-road though. But you could conceivably setup your buggy for on-road competition one week, then off-road the next if you wanted. Or just have two of the same.

Come down to it, that would make a really cheap on-road class. 1:8th buggies are all over the place. Parts support is right there. Throw an on-road body on it (universal body mounts from ofna) and there you go, rally game car. Or don't even bother with the body, just run an on-road setup with street tires/foams.