I bought a trailer hitch and wiring kit from Curt Trailer. Installed the hitch with no problem, but having a hard time getting the wiring installed. I was told by Curt that this after market kit was compatible with my Q7, can't seem to figure out how to install it. Lots of YouTube videos on Q5 installs, but none on Q7 . Anybody have any suggestions. Trying to avoid paying over a thousand dollars at the dealership. Thanks