Hi Smitty, i had to change this too, i've got an Eibach for 80.- swiss francs, 2nd hand. The problem on the mk IV it's the right semiaxis. It's a bit bigger than the left one and also shorter, so it works more on bumps and so on. So when u lower the car like you did (i have the same coilover as you), the OEM antiroll bar is touching on this! The Eibach it's bent in a different way and it wont touch against the semiaxis. Hope this helped you!
