Fortunately, today I saw a sportscar painted RACING GREEN. It was more a primary color racing green than a British racing green, but it looked pretty sweet. The magwheels were also green, except for the one which had been scraped up and was temporarily silver in places.
A new paintjob has to be cheaper than a new car, and it would also help you find your car in the parking lot. So there is some practicality.
Since today’s cars don’t have much shape to them, a paintjob designed the right way might make a boring car look pretty cool, by adding the illusion of shape.
And then, there’s always the great tradition of painted vans and painted Russian cars, which can now be achieved by using that vinyl photo-wrap stuff instead of actual paint. That way, you don’t have to sand down the car first, it’s cheaper, and yet it lasts 4-5 years. If you change your mind, you can pull the wrap back off, and everything on your car is the same as it was before. The only downside is that you would want to hand-wash your car while it’s wrapped – but I imagine dirt wouldn’t cling as tightly to vinyl. (And in fact, there are clear vehicle wraps that are just there to protect people’s paint from sun and weather.)
(Btw, here’s an article about dislike of the color green in NASCAR circles. Some regional groups of Irish people traditionally see green as a color that belongs to the Sidhe, and therefore unlucky for humans in clothing and some other categories. I don’t know if that’s where the NASCAR superstition comes from, but there are lots of Scots and Irish people in NASCAR country. Anyway, here’s more about NASCAR superstitions.)