The car is a 99, but I am looking mainly for where the harness plugs in and runs up front. I know it goes through the rear firewall and under the passenger seat, but from there where does it connect in for power, speed, reverse, illumination, iBus etc etc..

I saw those links, and I found the X5 cable harness routing, but it plugs in to X400 in the rear of the car, which my car and retrofit harness does not have.