Just finished the install with the F90BT yesterday in my 2000 Bonneville SSEI. I had to use the Metra GMOS-09 to use the factory bose amp. I wish I hadn't spent the money on that GMOS-09 because the volume level sucks. Very low volume, even cranked all the way up to 62 its just about normal listening level. I am not sure if its the GMOS-09 or the pioneer headunit. I assume the change lies within the GMOS unit. Only fix I know of is to do away with the bose amp and add an aftermarket amp with adjustable gain. Any suggestions? Where can one find an amp integration harness that will plug into OEM harness and RCA into aftermarket amp? Is there such animal and whats the model number? Or is this gonna be a cut and splice deal? I have all the diagrams on my snap-on software, just have not pulled it up at my shop yet. Thanks. J

This is a fancy version> http://www.myradiostore.com/noise-filte ... a-rca.html

I'm sure there are cheaper analog models without the remote. A PAC LC-1 would do the trick for under $15 as well.

These are both stereo models. For a 4-channel amp, you will need two.

the GMOS has it own set of ajustments on it, you should be able to turn them up a bit and make it louder