what's the faster wagon?

They also have wings at front and rear to exert a downforce well in excess of the car's weight. An F1 car could be driven upside down on the ceiling of a tunnel with the downforce produced by the wings keeping it on the ceiling. How's that for physics?

yep...watch what happens when one looses a wing at

If you have a big fat tire you can make it out of a really soft sticky rubber and not have it shred to pieces when you apply 1200 HP to it.

That is exactly my point. When you use soft surfaces like tires, then the whole coefficient of friction argument falls apart. Tires get some of their traction by actually sticking to the pavement and hence get worn down in use. On wet pavement, a whole new set of variables come into play and and tread pattern actually becomes a variable.

It changes the size of the foot print and can make the tire act like an undampened spring and become unstable like a car with weak shocks.

Only with soft tires, not with hard wooden blocks. This is a physics