I cross the border by car at St. Stephen, New Brunswick / Calais, Maine twice per year in the Spring and Fall and have been doing so for about 20 years now (my wife and I prefer to travel when kids are in school and no, I don't hate kids, just other people's kids).

Unlike Trevor, I've found the treatment fairly equal. My wife and I have always had passports and only once do I recall what I considered an impertinent question entering the US. We were going to visit a daughter and the guy asked "What does your daughter do?". "She's the mother of three youngsters", I replied, but thought to myself "What business is that of yours?"

Returning, Canadian border folks, seeing a Nova Scotia license plate, never ask for any ID; they are much more interested in making certain that they collect the taxes owing on any amounts above the $1500 CDN we are allowed to bring back. Since we always owe some (we declare honestly), we have to stop and go in to pay. Recently, the young lady decided that she would add up our receipts and got a different number than we had. She was going to get shirty about that when I suggested that she add them up again. Second time around she got an answer much different from her first (and from ours), so we settled somewhere in the middle.

I'm not quite sure why, but this reminds me of Dan Aykroyd in Canadian Bacon.

Trevor