I saw one of these kits last year on a red Miata. It looked pretty good at first, but there was just something odd about it...the proportions were off, of course. After looking at the car closer (namely, the interior) I realized it was a fake. You can put Type R stickers on a car, wings, coffee can exhaust tips, whatever, but trying to make your car look like another body style is worse than low. It makes you look cheap and untrustworthy.
The Miata isn't a bad car to begin with...any owner that uses a kit like that just isn't worthy.