Heat or GooGone? If neither of those work, the other alternatives would be to get some of those silly stickers to cover it, or just order euro replacement visors from e-acca or similar.
i'm gonna go the badgeskins route but did have pretty good results in my mk6 with rubbing alcohol - but like Jay said it leaves a little bit of a 'shadow' where the vinyl used to be, not a big deal though
3 years no peeling
clean with microfiber and 99% IPA (from drugstore) REALLY WELL
Apply when warm out. Leave clear backing on! Smoosh in morning. Go to work. Smoosh when you get back in car. Do this a few days then peel it off. Worked like a charm.
Badgeskins - I tried them and they didn't stay v. well and ended up removing them. Would not recommend. The visor surface just isn't smooth enough for them. Great idea though.