I wanted to add to this discussion as well. I'm having the problem that many of us have - door windows don't retract the 1/8" when opening the door. In doing my research throughout the forums I figure it's a bad microswitch in the locking mechanism. (The one that tells the car the door is ajar). Could also be one of the inner/outer handle mechanisms... but the symptom happens when opening from the inside or outside, so I doubt its both handles.
I wanted to add that I also found the same part listed in the eBay link above on AliExpress. Same part numbers, same stamps, same color even. But in the AliExpress listing it shows "Boxster 1994-2004" listed under compatible vehicles.
What do you guys think? Worth a try?
Aliexpress.com : Buy Door Lock Actuator Front Right For VW GOLF MK5,RABBIT PHATON 3D1837015A OE 3D9837016 3D1837016AB 3D2837016P 8N1837016A/C from Reliable golf mk5 door lock suppliers on safe driving Store