I want to replace my radio from my 1991 sl to a cd radio,my question are there wire connectors that are plug and play so I don’t have to cut and splice my wires together
also any recommendations on which radio single din is prefered
and do I need the code to install new cd radio

 

Your MY1991 probably has a two-piece radio with tuner-amplifier in the trunk. There is also a bass amp under passenger footwell mat. The original radio can be replaced but that is somewhat elaborate. Search is your friend; there are lots of discussions in the internet about the early R129 Becker 2-piece radios.

BTW, by now CD is almost obsolete... If your original radio still works, retaining it may also retain best your car's value. Many early car owners report they are happy with FM Bluetooth devices.