Apart from all the mechanical reasons, I think they're also starting to look their age. Look awesome side on, but the head lights and tail lights look terrible. If she's got the money, definitely get a Supra instead. TT models cost as much as a 33 GTR, but the NA ones aren't too bad. Don't tell any Zed driver that though, apparently they're nemeses.
Another reason not to get one is tons of dudes will follow her/harass her on the road. Especially if she has a big playboy sticker on the window, a custom plate, or any other indicator she's a chick driver.