If your 124 body is a US model, forget cuting the door panels for speakers. Your power window mechanisms will get in the way. Any goood car stereo shop can create pods to hold virtually any aftermarket speaker/tweeter combo. The exact color MBtex is available from any MB dealer in smooth or grained. When you spend time in a car stereo store, you will hear sales people talk about "rear fill speakers". This is a sales technique. You don't need to add more speakers to the rear, the ones in the corners are fine once replaced with any good coaxial of the same diameter or slightly larger. Forget the clips that hold down the junk paper cone oem speakers. Get a tube of silicone and lay a bead around the plastic cylinder before pressing your new replacement speakers into them. The only time rear speakers are required is when your CD head unit has dsp features that need four speakers to create the digital effects. When you go to a concert, where do you hear the sound coming from? It's in front of you, and always will be, so concentrate on a superb soundstage in the front of your car. If you really want to hear better sound, make sure to source SILK DOME tweeters and high quality mid-bass drivers.