Audi Repair Questions? Ask a Mechanic for Answers ASAP
Is this a Genuine Audi Towbar Electrics Kit you are using?
Is so then the wiring will either be fitted into the rear lamp units (you remove the multiplug and then you fit the connectors for the towbar wiring kit into this.
The other sort I have seen have a wiring loom that runs the length of the vehicle and plugs into a connector behind the glove box.
If you haven't got a Genuine Audi Kit I would suggest you purchase one as you can cause damage to the modules that control the lighting systems due to overloading the modules.