Not sure the year of the nomenclature change. The MBUSA.COM site has a page that profiles all their models for the past 15 years. I just now tried to get the link but the server seems to be down. Just go to the main MB site and look around. Let me know if you can't find it. Also, once you have the VIN, CARFAX will tell you what it is. I bought a 1992 600 SEL two months ago and am very happy with it. I see lots of discussion re: the 500E/E500, but the power to weight ratio on the 600 is virtually the same. I'm sure the E500 handles better, but my family and I took a 500-mile trip last weekend, and I can tell you interstate travel in the S600 vs. a regular car is the difference between flying in a private jet vs. coach in a commercial airliner. Check E-BAY for competitive pricing....