Replacing entire bose system in 2000 GTP

Hey guys, I know there are probably many posts about similar topics, but I havent yet found one wanting do exactly what I want. I'm looking to replace the factory head unit, bose amplifier, and all of the speakers in my 2000 GTP w/o onstar. The thing is, I do not want to chop any wires, as I want to be able to return it exactly to stock. I know it is easy to do on the non-bose cars, but I have not yet torn apart one with bose. I was wondering if, since I will be running new wires to all of the speakers, I can use a normal stock-to-aftermarket wiring harness for the head unit. Additionally, if there are any other tips, or questions for that matter, please let me know. Any help is greatly appreciated. Thanks!

I would check with the folks at Crutchfield.com. It seems they're pretty good at making installation as easy as possible. I have ordered speakers from them (not yet received) and they include wire adapters for plugging into the factory connectors. This link may be what you're looking for:
http://www.crutchfield.com/p_120701858/Metra-70-1858-Receiver-Wire-Harness.html

ya thats what is typically used for the non-bose stereos, but I was not sure if it worked with the bose ones as well. I know it would not work if I wanted to use the bose speakers and amp, but seeing as I intend to replace all of that, it may work fine

Here's a follow up. After replacing all the speakers (except those tiny things by the sideview mirrors), I still wasn't satisfied with the sound in the 98 GTP with "premium" (aka, Bose, Monsoon) stereo. So I talked to the nice people at Crutchfield and bought head unit, amplifier, subwoofer, and steering-wheel-control adapter.

I didn't have to cut any factory wires so I could return to factory condition, but probably will never need to. Put the amp and sub in the trunk, ran new wires to the door speakers. Used the wiring harness adapter provided by Crutchfield. It's a five-channel amp (four plus sub). So with six speakers to power, I wired the 6x9s and 5" door speakers to the amp and wired the 4" in the back deck back to the head unit through wiring harness adapter. The Alpine head unit will provide signal to the pre-amp outputs as well as the power outputs simultaneously. That was a convenient feature. (If I had planned on doing the whole thing from the start, I probably would have left out the 4" speakers and maybe have gone with three-way instead of two-way speakers.) I did have to splice into a factory wire for the steering-wheel-control adapter; used a "snap on" splice so no wire cutting.

I ran all the signal wire down the driver side channel below the door trim. The 4awg amplifier cable goes from the connector at the top of the engine compartment fuse box, down to the base of the passenger foot well where there is a rubber grommet for a wiring harness. Slipped through that same grommet, then down passenger channel under the door trim into the trunk.

Gave up a fair amount of trunk space because I bought a sub in a ported enclosure.

I am very pleased with the sound quality now. Installation was not too tough, just took some time. Figuring out how to get the power to the amp was probably the biggest challenge. It sometimes changes volume on its own now (decreasing) and I wonder if that the steering-wheel-control adapter misbehaving.

For those interested, I got an Alpine head unit w/o CD but with a USB and mini-jack input. The head unit will control an ipod through the USB and should also play from a USB drive (although I haven't done that yet). It's a 650W high-sensitivity (87 dB) Alpine amp. Cheaper amps had sensitivities about 65 dB...and 20 dB is a big difference worth paying extra for. Other amps with similar sensitivity were significantly more expensive. Kicker 6x9s and Blaupunkt 4" in the back deck and Kicker 5.25" in the doors. Left the little tweeters disconnected. Oh, it's a 12" JL Audio sub.

The folks at Crutchfield were very helpful and patient. Had long "chats" with them three times before settling on my equipment.