Sorry to drag this back up... but I was round at my mates house on Sunday and he has a 56' plate R32 - which is black.
I checked the paint on the A-frame and its exactly the same as all the others. About 3mm of normal paint visible, then it changes to primer.
I also checked mine, which is the same, but its much harder to notice on silver as the primer is almost the same colour! You can just see that it changes from metallic on dull paint.
Definately looks like this isn't a 'problem' as such - just VW being cheap and lazy... and that they've been doing it for at least the last 4-5 years!!