That'll have to be left up to Erik.

I quite like this wheel, its silly, but charming. I am wondering whether it would clip through slopes, or change its angle to accomodate to them?

I'm not a modelling pro and don't know the terminology that well, so I doubt it. That, and the car's kinda supposed to be big, but I can try to make it smaller tomorrow if the need arises.

Other than that, I like this wheel

Have you tried out smooth shading and edgesplitting? also, the car sticks out too far.