I don't claim to know but I can only think about the way I have perceived cars myself. It used to pain me to have to spend a few thousand dollars for a secondhand car, which was basically an object performing a utility function for me. During that time of my life, when I saw long stretched limos I used to think that that's how the wealthy live. The point being that when cars did not matter all that much, that's when I perceived them as being prestigious. Of course with my changed mind-set, they now look cheap to me. But maybe the majority of people for whom cars are only utilitarian objects find the stretched limos desirable?