If I bought a MB from Canada and drove it down to the US, does the warranty still apply? Thx.

all the dealer has to do is run a VMI and the in-service date will come up. That's how they determine warranty work. As long as the car comes in the VMI, it will be covered. Might want to contact MBUSAs 1800 # (can't remember it now) but you can get it off the website. they can give you all the needed info.