Originally Posted by noah

I've driven many rental cals across the border, both US cars into Canada and Canadian cars into the US. I've never once told the rental agency that I was doing this trip, never once had any issues. A few times I was asked by the agents if the vehicle I was driving was my own, and I responded "no, it's a rental" and that was the extent of it -- never had a contract verified or anything like that. I don't think you'll have any issues.