In this case, the mechanism holding the car to the road is not relevant. The important part of the visualization is the implication of all wheel rotating at the

In this case, the mechanism holding the car to the road is not relevant. The important part of the visualization is the implication of all wheel rotating at the same speed on a curved surface. Any visualization on Earth would have this problem, because gravity effects the possible configurations you can think of. If it makes you feel better, move the car and road into space and hold them together via magnatism.