Issues with brake lights, turn signals, and running lights in the rear of the car everything to do with the front end lights work just fine. Could this be a wiring or CECM issue? Because the owner before me had done some weird custom wiring for the back tail lights and volkswagen corrected the wiring and now the lights do not work at all i had taken the vehicle in a few days ago and they said its a possible wiring or module issue how would i go about fixing and diagnosing the issue so i do not have to spend a fortune at the Volkswagen dealership to correct it. I will provide some photos of the wiring if needed thanks, Tyler