Upvote:1
We have crossed the Canadian border many times in a car, with multiple people having passports from a European country with Visa waiver status. They flew in the US (having an ESTA), so this should be the exact situation that you describe.
In every instance, the Canadian border officers took our passports (handed through the driver's window), asked some question about visit duration, potential weapons, drugs, and alcohol, and spent maybe a minute offline with the passports. Then they handed them back, and that's it. No need to leave the car.
On the way back to the US, the questions are slightly different (no alcohol limit, etc.), but the process is the same; sometimes they wanted to look in the trunk, but never bothered to look inside any luggage (I assume they look for people hiding in the trunk).
This experience is from 2017 to 2019, on the Rainbow Bridge, on the land border south of MontrΓ©al, and in various small crossings from Maine to New Brunswick and QuΓ©bec, overall maybe 12 crossings.
I don't think you need to be worried in any way, if your passport is ok, and you haven't overstayed or are wanted by the FBI.