What about a category where you can only drive in reverse?
What about a category where you can't drift?
What about a no wheelie percent?
No Trick percent?
Reverse would be unbelievably mind numbing to play
No drift is the same as automatic only, since no drift manual is leagues slower
No wheelie is basically just karts only
Reverse only would not be entirely possible either, because boost panels send you forward, and you can't go around all of them. Canons also turn you forward automatically, but that wouldn't be as much of an issue because you can back into them. You'd just have to turn back around again once you land. Besides, if reverse only were done in VS mode, you'd never be able to beat the CPUs. It's an interesting thing to think about in theory, though.