Specific wiring for retrofitting the original swivel trailer hitch for Audi A3 8V all functions are supplied as factory installed Scope of delivery: Cable set Notes: After installation, the control unit must be coded using the item number 42239 the appropriate trailer hitch, control unit, button and cable set for the bumper are also required We can gladly make you an offer for the complete retrofit swivel trailer hitch only from model year 2017 possible Up to model year 2016 you can retrofit the detachable trailer using this cable set up to Mj. 2016, with this cable set the detachable AHK can be reinstalled