UPDATE @ 07/31/11: Photos of the detailing of the rear of the car a on a separate post...
I raised the car on jack stands and removed the front bumper cover, headlights, wheels and wheel well liners to have better access. A mild degreaser, brushes and shop towels helped to bring the original shine back.
The plastic liners cover a large area of the wheel wells keeping most of the grime out however, there was still quite a bit of dirt behind them.
I think the front suspension turned out OK.
Once I completed both wheel wells I turned my attention to the underside of the engine from the lock carrier back to the subframe supports. I was glad to see that the sound dampening pan has done a pretty good job keeping dirt under control. The exposed sections of the sub-frame and the transmission, however needed some attention. The best thing of all is that there are no leaks back there!
The engine crankcase has never required much attention to keep it clean.
The ZF transmission (5HP19FLA) was a bit grimy but was easy to clean with a bit of degreaser.
The housing of the Torsen differential and surrounding heat shields are sparkling again.
The sound dampening pan (or belly pan if you like) has certainly seen better days and is even missing a small piece but it is still looking better that others I have seen around the Web. Hard to find an excuse to replace it at this point. Did you ever stop to think that your Passat has NACA ducts just like an aircraft ;-)
All buttoned up and ready for a few more years. I hope...
Well there you have it. That is as clean as it will ever get.