I have a set of 4th gen leather seats with lumbar (no power driver seat) that I'm planning on installing. They did not have the wiring or compressed air harness but I picked one up on Ebay.

The harness has identical 6 prong plugs on both ends along with the air and it has the 2 prong white power plug on one side of the harness.

Since my car now has power seats, it has wiring running under the drivers side seat. Does it matter which end of the 6 prong harness plugs into driver or pass side seat? I know that the compressor is located under the pass side seat.

 

I made my own harness with icemaker tubing and 18g wire, but all you really have to be careful for is not crossing the lumbar tubes...thats really all that could go wrong.