i think they all come with front mudflaps, and i know they all come with center mudflaps. i plan to install the rear ones before next winter so that i no longer have to deal with road salt being kicked up on my rear panels.
The rear mudflaps are great. They look good, and more importantly, they keep the rear bumper much cleaner. The only cars they won't fit are 9-3s with the SE rear skirt or Viggens. I miss my rear mud flaps now that I have a Viggen bumper on my 900. It gets so much dirtier.
Fact is rear mudflaps (is this even the proper terminology?) are very rare on coupes and sedans and basically anything that is not a pickup truck.
If you wash your car yourself and constantly have to clean the area that would otherwise be protected by a mudflap, you understand their value very quickly. I don't care if they are deemed "unsightly" by others or the general automotive public, they look cool IMO and give the car that rally car appearance. Form and function.
And no, my aged '95 900S has never had them installed.
I know, at least, that they do not hang down like the mudflaps on tractor trailers (18 wheelers or what have you) and they are streamlined in appearance but I'm curious as to how they really look, especially with some nice wheels.