I don't know Brazil, but based on what I know of the US I wouldn't be surprised. A couple will often own 3 cars, 2 daily drivers and one for some other odd task (truck, or the sports car) that is used as a backup. It will be one car per kid of driving age, though most kids are not old enough to drive. Then there are work cars, which for tax/legal reasons can't be used for personal trips so those who have them will also have a personal car for non-work trips. There are people who keep a car at their vacation house. Rental cars also add a fair number of cars. Plus collectors who have a dozen cars that they only drive to shows. It all adds up.
The more important metric is that there are only 238 million licensed drivers in the US.
So if every single licensed driver went for a drive, they could invite all 26 million licensed Canadians to come down and use a spare car, and still have 22 million registered cars left over.
