Okay so hear me out. In Cars 2, on multiple occasions, Sally and other female cars are swooning over Francesco’s open wheels. Apparently these are attractive in the cars universe. Anyways, later in the movie a car without any tires is shown going through a metal detector at an airport. This is clearly a parody of people having to take of their shoes in real life. Using this knowledge, it is safe to assume that wheels are the equivalent of feet in the cars universe. This means that many characters in the Cars universe have foot fetishes and are very open about it.