Originally Posted by vadim321go
regarding rms, u want the highest rating possible. dont even look at decks which have below 17 rms rating, they are too weak. if u find a 23 grab it, but the higher the rms the mor expensive it is. when installing teh deck ur gonna need 2 things, a wire harness and a radio adapter. the radio plug in bmw's is not standard so in order for u to get radio ur gonna have to buy it. as for the amp, ur gonna have to bypass it
I installed my Alpine head unit last week and didn't bypass the amp and it works.(At least I don't think I bypassed it) I was having troubles at first of no sound coming out until I hooked up the last blue wire left on the harness adapter, to my Remote Turn On wire on the head unit(I think that's what it's called, it turns on the amp, aftermarket or factory). And that did the trick and so far so good. And the other part you need is the radio antenna adapter.
So to answer your question, if the head unit has a Remote Turn On or Amp Turn On wire, it'll work.