Though this thread has started some time ago, for future reference I'd like to point out that the warning about potentially bending a fuel line while removing the driver's side valve cover should be heeded. I must point out that the line discussed is not the the fuel return line - it's the actual fuel supply line. Kinking it will reduce the fuel supply to the distributor. Just as Thomaspin suggested - make sure you use two wrenches.
1989 560 SEL (black/black)
2001 Audi TT Roadster (silver/grey)