I have a 1994 C180 Euro version and the in-built speakers are a bit cheap sounding. I wish to put in 2 or 3way speakers in the 4 doors and also in the back deck, but need help in getting into those places. How do I open the door panels and the rear deck? What size speakers, how deep they can be to fit the spaces and what ohms are correct? 4ohms or 8ohms? I have a Eurovision radio cassette with CD controller to control the 10disc stacker in the boot also Eurovision(or Sony). The present sound is quite flat at full bass and the treble is not loud enough to be heard in the back seats. Sometimes at full bass, the front door speakers do rattle and shake, unable to cope with the symphonic sounds I love. Thanks.