I have never once thought to myself, "This driving experience is so much better because this car is so pretty!" Better handling, more power, smoother ride, more comfortable interior, sure, all those things improve the experience. I'm also aware this is an opinion, where people will have different experiences, but unless you live in your car I can't imagine paying extra solely because you enjoy what that extra brings. The reasoning that causes this simply doesn't make sense to me, although I acknowledge that it happens (a lot).
And while the 99% number is incorrect, it is about as absurd as the 50% claim. Upon actual research rather than my gut instinct, this site puts the number of cars on the road after 20 years at 24%. Note that the weather where I live is harsher and the average age of cars is about a year less than in America, and that the distribution doesn't follow a normal curve so that percentage could be a few points lower where I live.