If you look around you can find quite a few 'S' models on Craigslist that aren't quite an S. I suppose if you stick enough S's on it an uneducated buyer won't know any better.
Here's a 1999 Boxster S. Looks like an S, maybe they got the year wrong:
1999 Porsche Boxster S Pristine Conditions! Very Low Miles!
Here's a 02 Boxter S "sport edition". The Sport edition S comes with a 5-speed (and 2.7).
02 Porsche Boxter S sport edition convertible
