After looking at UOA reports and also confirming the newest GC does indeed meet qualifictions for VW 502 with a HTHS of 3.5 I decided to go ahead and fill with it at the time of my latest turbo swap...
The car is a 2006 Audi A4 2.0T FSI that has a 5 quart sump and upgraded turbo charger with no cat and full exhaust. Since my oil change intervals are only 1K to 5K miles depending on conditions, I figure stepping down to a 0w-30 may be ok to do. Just to clarify there is rumor that GC 0w-30 is factory fill for Audi and it is not. Audi factory fills with a 5w-40 oil. But i'm hoping this oil will provide the protection I need while possibly freeing up 5hp or so. I'll do some analysis to see if it hold up. Thanks for the help you all have given.
cheers! Mike

