Yeah, because I rarely lose races in 150cc and Mirror MKDS unless I just got up, or something. -_- 250cc would be an excellent challenge.
I was once working on a Mario Kart game where, if you were bad at 50cc, you would unlock 25cc, then 10cc, but if you were good at 150cc, you would unlock 250cc and 500cc. Obviously, I ended up discarding the project.