Amplifier by-pass harness
 

Finally, after a year with a cracked rear window I now replaced it with a Robbins glass top.
With this comes a re-ignited interest for the car, it looks like new on the outside even though it is a 2000 2,7.:)
Decission right now is to continue with the stereo upgrade, new speakers already installed but sound is still really crappy. Figured out it has to be the Nokia/Haes amplifier with its built in hi and lo pass filters that is the reason for this.
Still, a lesson learned manymany times is that it would be great to keep the car in a condition where it is possible to go back to stock in 30 plus years something. So question is if there is any harness kit available that can bypass the installed OEM amplifier and just use the head units built in amplifier directly to the speakers, or a temporary replacement amp that is possible to remove without cutting to many cables.

Crutchfield: Car Stereo, Speakers, Home Theater, Pro Audio, 4k TV

I don't know if this company can help you. There tech support is really very good. I have used them for +/-4 vehicles in the past. But none of them Porsche's.

I looked everywhere and there isn't much for us. I used CAI which specialize in Porsche stereo installs. Not cheap but the wiring kit they sent me worked great. I did have to cut the amp harness but I added a new amp because I have an 03 which is MOST (yours is not) Anyway contact them...he was a great source and very helpful. cai-store.com

Call Crutchfield. Metra packages and sells their wiring harnesses through them. If it exists, you can find out in a simple phone call. They have the great customer service and support.