The Track rod ends can be a right pig on Audi's just like the pinch bolt for the top arms. Keep it wet with WD or something. That said mine were ok on the front but the rears need some work.

Yeah that pinch bolt is a right arse. R8_Dream knows a guy that sells a tool specifically made for getting that pinch bolt out. I'll text him and seen if he knows the company name, it's not cheap though.

Loctite Freeze&Release does the job fine for most of the time. Don't know why it is not popular here in UK or easy to get. You can get some on e-bay

http://www.loctitefreezeandrelease.com/