It was build from Westfalia for Audi,
these are the towbars you can use up to 2100kg.

The cheap aftermarket yo can find at ebay the can only 1400kg
and you hav to cut out a big piece out of the read bumper.

Wiring harnes is not a proble, as far as i know,
you need a lightcontrolbox for towbaruse.

Gude Mario Audi 100 CD Autom. Bj.83 Audi 200 20v Bj.89 Audi 5000 Bj.85 Audi V8 3,6 Autom. Bj.88