No bounce as there are no polygons to bounce on, and no sinking if you have to much torque. Realistic grip, endless possibility's so on and so forth.
Here is a release to the contraptions thread.
Its the wheel2 Stool which appears in a tab at the bottom of the wire menu.
All credit goes to Satri-Ali as all of this is his work.
Enjoy having much more realistic wheels in garry's mod.
make sure you no-collide the wheel to your whole contraption as it has a much larger radius of collision than you might expect as it draws an invisible sphere, not a wheel sized cylinder.