The first SLK car was based on the R170 platform. The first model was the SLK 230 Kompressor. It had a fairly powerful supercharged I4 engine, but it was weighted down by the retractable hardtop system. Only automatic transmission was offered on these cars, disappointed some Mercedes buyers.
A manual transmission was added for 1999, and the engine was upgraded to a 215 horsepower V6.
2001 saw the introduction of the first AMG version of these cars. AMG is a performance branch now part of Mercedes Benz. The SLK 32 AMG was a 354 horsepower beast.
Some of the earlier models of this car were the SLK 200, SLK 200 Kompressor, and SLK 320. The Kompressor name means the engine is supercharged.
The R171 platform was introduced in 2004. The new models are the SLK 200 Kompressor, SLK 280, SLK 350, and SLK 55 AMG. The AMG is electronically limited to 155 mph, but it could go much higher with a little computer "tweaking."
These cars are not easy to find used, but there are some places that are almost guaranteed to have a few for sale. One such place is eBay, believe it or not.