Yup I know rear pdc is disabled if it sees a load on the hitch electrical outlet however LEDs didn't work for me and I had to rigg up something that mimics loads that are equivilent to lamps. Btw it requires loads on brake, blinkers and plate lamp.

Unfortunately even after all of that the tow hitch electrical system still throws out errors that are logged by the car.

Why the hell you have to go to this much trouble to simply disable rear pdc is a joke. BMW are aware of the issue as I've spoken to one of their NA reps about it but they don't have a easy fix as it requires "extensive" re-engineering of multiple systems and it's not cost effective to fix.