Hi Paul
I've done a lot of research on the Tow bar and electrics and the Trailer stability Programme. TSP will only work if the OEM(original equipment manufacturer) trailer wiring looms plus trailer control module are fitted and the car is then coded. I went down this route buying both the detachable towbar and wiring looms via westfalia at about 2/3 the cost of VW dealer. The Towbar was easy to fit in about 2 hours but the OEM wiring looms took about 2 days!!! they are quite complex and not for the faint hearted involving the dismantling of a fuse panel and terminating in the back of same. Followed by dismantling 2 existing wiring loom plugs and removing/replacing individual wires in same and that is apart from removing most of the trim from front to back of car on both sides as the fuse panel is on the near side but the 2 plugs are behind the dash on the off side. There is also a seperate loom to take to the Battery in the engine compartment for caravan battery charging / Fridge.
Having done all the hard work my VW dealer then wanted to charge me £242 plus vat to change the 4/5 codes needed to activate all the facilities (Trailer function / TSP / parking brake / ABS / Alarm ). I tried local independant VW experts but unfortunately the car is too new so I bought the VAG-COM software/lead and coded it myself (with some help from westfalia).
If you fit a detachable towbar I would highly recommend buying the VW lower bumper (the black bit) that has an access cover built in.
I forgot to mention all this only gives you the continental 13 pin socket so you either have to use an adaptor or rewire the caravan.
I am extremely pleased with the end result but I now know why my VW dealer wanted to charge £1200-00 to fit it. I have also told my wife that if I ever say I'm going to fit a towbar to another new car she should hit me round the head with something heavy!
If you still want to go ahead and need any other info either email or PM me
Paul (lefrog)