The retractable rollbar could also be raised or lowered manually using a switch on the console, and facilitated occupant safety without compromising aesthetics. In 1992, R129 was the first SL-Class to offer an optional a V12 engine (600 SL/SL 600) and to have official AMG variants (500 SL 6.0 AMG, SL 60 AMG (V8), SL 70 AMG (V12), SL 73 AMG (V12), and then SL 55 AMG (V8)). The R129 was the last SL-Class offered with a manual gearbox.

For the US market, R129 was the first SL-Class offered with six-cylinder inline engine from 300 SL-24 (named as 300SL) since the 1971. For 1995, a larger 3.2-litre engine was introduced in the SL 320, subsequently dropped from the US market in 1998.