you'll need the trailer module too, it sits in the battery compartment, along with the PDC module. there is a wiring harness that attaches to it and runs out the back to the hitch connector.
With my hitch, I had to remove the cross bar that goes between the bumper supports. and replace it with my hitch assembly. the hitch retrofit installation instructions are great!
I agree with the other posters, no response since January?? time to contact a wrecker, they are pretty good with stuff like that! (up in Canada anyway!!)
good luck!

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2003 X5 3.0i (02/2003) sport package, Sapphire black metallic / Black Dakota Sport seats. compass mirror retrofit, trailer hitch retrofit, Prodigy P2 trailer brake controller installed, PDC retrofit, Lumbar support retrofit. heated rear seats retrofitted. Running boards retrofitted and subwoofer install in progress. 4.8is Brakes installed front and back. Bluetooth TCU installed, Rear Fog lights installed. Retrofitted reclining rear seat backs.