I have a 96 S500 and I have two cup holders built into the center console beside the phone. The console is a two part contraption with the bottom part fixed with a slider over a compartment that holds all the crap that ends up in a car. The top part opens to hold the phone and there are a couple of drink holders there. I don't know if your 95 is the same but apparently not. I did buy a cup holder from www.griotsgarage.com
that supposidly is the one used in a later SL. I got it and it looks great, but I just can't bring myself to mount it on the driver side door with screws. You might ask, why do I need another one if I already have two?. Answer is I don't like raising the armrest on the center console to get to the drink holders. I like resting my right arm on the center console and I can't when I have the cover up with a travel mug in the cup holders.
I don't use the phone as it is an older analog model, so I really want the center console in the down position.