I crossed this past Thursday. What a debacle! AND.. I don't blame them.
A new job I'm on is for a company that is based in Canada (Toronto) and has an office in Buffalo. I went across the border with a co-worker who is an English citizen with a 40 year old green card, that has a Texas drivers license. Turns out that because he is an English citizen he didn't have to have a passport to get into Canada, just the green card.
I was driving a car with Ohio license plates that is registered to a Pakistani living in Buffalo. (He's the warehouse manager in Buffalo. )
Needless to say, the fine folks at the border were a little suspicious.
It took a while to explain the whole thing to them, and they spent alot of time on the computer and a few phone calls. They inspected the entire van, but eventually let us in.
Coming back later in the day was more of the same, but it appears that they must share enough information, because the agent on the return spent a lot of time reading the computer screen. He advised the guy from England/Texas
to get his passport updated so he would have a more current photo.
No they didn't stamp anything on my passport.