Brian, while that stuff can help with fuel separation and all those other good things that happen with ethanol, the biggest issue IMO with carbureted engines (air cooled cars and bikes in particular) is that Alcohol (both methyl and ethyl) has a much lower energy density than gasoline. So not only do you get inferior power/economy but your properly jetted engine (on gasoline) runs lean on ethanol. Even worse when it separates and the low grade (low octane) base fuel allows detonation.
When I restored my RD400 Daytona Special, a couple guys had blown theirs up on blended E10 fuel.... granted they were carbureted, air cooled *and* two strokes, but still..... I was glad for the warning.
In BC, Chevron 94, Shell V-Power 91 and (surprisingly) Costco premium fuel are all ethanol free. I stick to those ones for the VW.
Steve