No problem!
I drove our own car, but the car is already registered in Ontario, so that was not an issue for me.
From what I understand, you first have to export it with the U.S. and then import it into Canada. Nothing difficult, but some paperwork based on what I've heard.
Thank you for the link to your post, Karlshammar. It was very informative. One other question for you. Did you drive your own vehicle and was it already registered in Canada? I was thinking of driving my sponsors vehicle, but don't know if that will give me problems (he won't be going with me). My vehicle is registered and insured in the US, but the tag appears expired due to problems with mail forwarding.