I bought a pair of Kenwood 5 way 6x9s for my R53 last night. I have the drivers side done but what a pain in the ***! Am I missing something? the whole interior trim has to come out to change a speaker, huh? Holy crap.

 

I have yet to tackle that, but from what I've heard, the first thing to go in on the assembly line is the speakers, then they built the rest of the car around them

 

It is not that hard to replace the rear speakers but yes, the rear seat bottom and seat backs (in that order), the rear trim panel in the trunk and the side panels do need to be removed. It goes fairly quickly once you've done it the first time and having the right tools to pop off the plastic clips is a big plus. Search on this forum for instructions on removing the seat backs... the first time is a little wierd but after that, piece of cake!

 

the door speakers aren't much more fun than the rear speakers.