Had problems with many other makes with the blower motor (Honda, Nissan, Isuzu) so it's not just vws.. it's pretty common
As for the door locks, that is a vw thing the b6 passats do it too. The reason it happens is because water gets inside the door (normal) and then in the lock assembly (not normal, should be sealed) and then it freezes. Don't try to slam the door when that happens, nothing will get fixed and you'll break the lock for good..
**EDIT** just saw you said ignition lock. Nevermind, never heard of that. The only ignition problems I've seen was from those 16 year old girls in beetles that have 5 pounds hanging off their keys. It kills the ignition lock quickly.