A big spike sticking out the top could change the center of mass and the moment of inertia. Both of those could affect how the car handles even if the spike nev

A big spike sticking out the top could change the center of mass and the moment of inertia. Both of those could affect how the car handles even if the spike never touches anything. Oh, and they can affect the mass. If the grip of the wheels takes into account the normal force, extra weight may help with traction. Hmm, and a 4th thing: some cars have a spike sticking out back behind the back wheels. These spikes sometimes function like wheelie bars, which are used on drag racers to prevent the car from flipping if the front end lifts off the ground. The wheelie bar kind of braces it but also lifts the traction wheels off the ground so they stop rotating it at the wrong moment.