As far as I know of have ever seen/heard/read the DOHC V12 can only be taken out to approx 7.3 to 7.4 liters of displacement. Perhpas someone had supercharged a SL600 and turned the number upside-down? I don't know of anyone who does superchargers for the M119 V8's or the M120 V12 but just about anything can be had at a price. I have always been told by everyone, that turbos or blowers wont fit underhood of E or SL cars. I believe you saw something quite unique but I have seen many poser benz out there. One of the most common is badging a SL320 or SL500 with the SL600 and V12 emblems. Something akin to all the bimwads putting ///M badges on their non-///M cars. (that means YOU 325i owners) I'm sure the owner reworked the exhaust system pretty heavily. The "Bad Ass Benz" Renntech V12 had a very impressive exhaust note... Every tuner car I have ever seen had enough badges to make their idenity quite clear. (even if the owner removed the badges, little things like muffler tips or front air dam plating would be a giveaway) Any tuner capable of creating something like that would surely want to leave their "mark".

My best guess would be he had a custom exhaust, flipped the 6 to read 9, and plastered a Kompressor badge on to boot. You should of followed him to find out what it was! Line up next to him at a stoplight, if he just wins...its a SL600 with some small toys...if he goes off like a 10 second NHRA car then I could be wrong.

Lee