Well, this is 2 different matters. The 722.6 trans was used even earlier than 97, I believe it was 96, but only in certain models. I believe it started out in the 140 and 129, but again, if in doubt, look for the "W-S" switch on the shifter plate. The trans that Davis is asking about, I'd have to look it up to be sure, that's what I do if I am doing a service on a non-722.6 trans is look it up and not guess. If it ain't electronic, it's probably a 722.3, could be a 722.5, sorry i can't memorize one set of minute details about one "era" of cars and learn the new stuff. I don't have to KNOW everything, as long as I KNOW where to find the info, that's my philosophy. On FSS, that was also a phase-in, it did start I think it was later in 97 some of the cars were getting it. By 98 I believe everthing had it, but you could tell they were "forcing" the issue. Some of the cars still needed the plugs done at 30K or 45K. The bigger problems were the older tech engines like the 111 and 104, which were used in the C230 Kompressor, the SLK230, and the S320. But the do have FSS maintenance sheets for them, so yes they were FSS cars. Once the lines were upgraded to newer tech engines, the 112, 113, 111 EVO motor, and now of course the 137, everything is a little more streamlined as far as the maintenance concerns, much easier to keep track of what needs to be done......Gilly