After doing some quick research, it has to be a Calloway. No one else made turbo kits for those cars. They were quasi-factory approved with the kitted cars available new from certain dealers on the east coast, complete with warrantees from an aftermarket underwriter.
Here is the recent thread from Fred on the one in his shop, apparently these Calloway cars are extremely desirable.
http://forums.pelicanparts.com/off-topic-discussions/773349-check-out-awesome-scirroco.html
Mk1 Sciroccos in general have become quite collectible. Incredible styling+decent performance+relatively low production numbers=collectible. Combined with the fact that they were not considered special enough to preserve when new and most wound up in the junk yard, equals a very small supply of good ones today.
Keep in mind that the owner of the one I saw today may have zero interest in selling, but I can dream until I hear for sure.
