I'm new here and a little late to the game but having spent this whole weekend trying to fit a towbar to my 07 A4 Avant I just had to add some comments.
Ok so firstly the guide above is amazing and anyone about to undertake this project needs it! but i would like to add some foot notes and amendments to help those of us new to the world of cars with this modern voodoo electrical mumbo jumbo.
- the purple lock on the back of the fuse box slides approx 2-3mm which then allows the individual terminals to be removed and inserted. There is a small locking tab about half way up on the right hand side when looking at the wire side. and the whole purple clip slides down. (kept in orientation of picture in the guide). The amount of force needed to do this is about the amount you need to break it so you have been warned.
- If you think you can do all the work yourself and then drive to an Audi dealer for the activation. (this is what I thought) the lights don't work...any of them. this is where i currently am so have just ordered Vag com hoping this will make everything work...
- when reconnecting the batter my keyfob was no longer programmed to my car no problem to reprogram it you do the following
1 hold the unlock button
2 insert key into ignition
3 turn on ignition and count to 2 (slowly)
4 turn off ignition and remove key
5 stop pressing unlock button.
Oh and 1 more hole I fell into with this job. despite what numerous tow bar suppliers, ebay, towequipe etc tell you a towbar from a pre 2004 car will not fit a post 2005 car. the mountings are different and it just wont fit!
On a related note if anyone needs a fixed flange bar for a 2001 - 2004 A4 I have 1 for sale for £50 all fixings included.
cheers
Steve