Ok.. I noticed on etrailer dot com that they have there own wiring kit . has anyone used it?

And what are the reason to have the dealer program it with a OEM harness rather than a after market one. I assume you don't have to have the truck programmed if you use an aftermarket wiring harness

Here is a link to there install.

Tow Ready Custom Fit Vehicle Wiring,Wiring for BMW X5 2010 - 119190KIT