Car Audio for BMW

It looks like you are doing a good job with it.  The wiring sounds right.  I am a fuse person, and I think the REM wire needs a fuse, too, because it will be connected to a voltage source.  I use a small inline fuse holder (49 cents) with a 500ml amp (1/2 amp) fuse in the remote wire.  Like  this and this.  So I suggest fusing the wire before powering up.  But, the deck should have a blue or blue/white wire to connect to the remote wire.  It is a switched 12 volt source, on when the deck is on, turns the amp off when the deck is turned off.Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Everything seems to be right. We went out and bought the inline fuse holder along with the fuse that you ahve suggested. We attached that about 1 ft away from the amp. We did this incase if the fuse was blown it would be easy to check instead of pulling out the deck. then we ran the rem wire to front of car and did not connect it yet. Our next step is to run a second pair of wires for a secon amp which will power the reare speakers only.