Re: B5 Passat - Power seats into non-power equipped (gtidog)
There is a user on the Vortex, larsensa, that is in the middle of this. I helped install the seats and he is getting them wired up soon. He could probably help you out with more specific questions.
I do know that Passats without the power seats standard are not equipped with the proper wiring harness to do a "plug and play" install.
Hope that helps.