okay i have never seen anything like what is going on with my bonneville stereo replacement. first off nobody know anything about them or they are afraid to even try so here is the skinny because i just finished my worst nightmare. first off i have the cd/tape deck the has the"ribbon" coming out of the back. the problem with removing these radios is the gm has so nicly added other bits of electronics intp the radios chassie. this is why no one will try this. in reality there is electronics in the radio chassie but they just make the audible ding when you door is open or when the fuel low ding. that is it. now if you have to have this then you can get a cable to relocate your radio somewhere else in the car. then you simply hard wire your radio and go from there. i finally found what i thought was the miricle harness but it was still lacking. it does give you the ability to connect to the front speakers though. it is a little hard to wire to a ribbon. but it harness did fail to power up my alpine. i took a volt meter and the wires that the kit says are a constant 12 volts are. the problem is that the lead they say is switched 12 volts is not. to make it worse there is not switched 12 volt source on the 32 pin connector. not sure how the stock head unit did this but the volt meter does not lie. so i ran a new wire to the fuse box and was good. now the front speakers are another problem. if you have looked at the kick panel area on a 2000 bonneville you will see that there is no way a human is going to get speaker wires into the door. this is why i was happy with my wiring harness that did nothing for my radio. it gave me a point to wire in my amp speaker wires. this also made it possiblre to use the stock door wiring harness which is a wonderfull thing if you have ever had the door panel that holds the tweeter and the mid is in the door. the rear speakers where the easiest part of this install and they where not that easy. you have to take out the whole backseat to get to the package tray. you can do it one of two ways. i could not get the tray tortaly out of the car so i just bent it up in the middle and stuck my light in to hold it up. i then out in my new speakers. not fun but still got it done. so here is what i installed:
alpine cda-9813
alpine cha-1214
jl audio 4504
planet audio 1200d
jl audio 3/4" tweeters
jl audio vr650 cxi
jlaudio v690 lx
3 jl audio 10w6

We have a couple 2000+ owners that have done this. Let'* see some pics of your setup.

That'* cool man, we have the same 4 channel amp, question in reading your install, you had to hardwire your headunit in the car somewhere, I know that some cars need to be done this way, but my installer was able to get around it. The stock Bose is sitting on a shelf.

Welcome to the club by the way. Lets get some pictures up!