Ah right, so is that even true of the Monza Shadows on the MK6? Are they ploughing on defiantly producing a wheel that corrodes after time?
Unfortunately i think that in time it's inevitable that the Monza shadows will corrode, As Greeners has said with the right care it can be delayed but as soon as the lacquer is compromised any polished finish will start to go
Best bet is to avoid any harsh wheel cleaning compounds and touch up any stone chips to the lacquer and avoiding salty winter roads will help enormously too!
VW doesnt have a great recent history tbh, MK3 Anni and MK4 Anni wheels both corroded with VW eventually admitting defeat with the MK4 and making the warranty replacements painted finish, MK5 Monza 2s (including the ones on my new at the time GTi) are notoriously prone too and the MK6 version will eventually succumb imo..
My OEM BBS spilts on my A3 had a diamond cut lip and they were replaced under warranty for the new ones to do the same! I'm super careful with my car cleaning regime but cant stop the tiny chips to the lacquer that all year round use brings etc