My neighbors have every inch of the garage filled with "stuff" so they have to park both cars in the driveway. I often wonder what "stuff" is more valuable than the price of 2 vehicles!
The first home I bought was a condo that had a one car garage. The condos were arranged in quads, and in our little parking lot, there were four one-car garages on either side, or 8 total. Of those 8:
3 were used for storage of junk/boxes/furnitue/etc
1 had a small pop-up camping trailer in it, with other junk piled behind it
1 had a motorcycle, on a small motorcycle trailer, and junk.
1 had an untagged Chevy Cavalier being stored in it.
1 (mine) was being used to store an antique car. I'd alternate between a '67 Catalina and a '57 DeSoto Firedome...whichever one wasn't at my place, was garaged at my grandmother's house about 10 miles away.
1 was actually used for its original purpose: to park (not long-term store) a car! Ironically, the one guy who regularly parked his car in the garage wasn't so good at it, and would occasionally scrape the sides of the door opening. I think he bumped his neighbor's Ram once, too.
To be fair though, the garages weren't that big; I'd say about 10x20 feet. Mine was the only one out of the four that was arranged so that I had a door that went into the entry foyer, on the left side of the garage as you faced it. When I parked one of my cars in there, I'd have to put as far as I could to the right, so I could get the door open to get in and out of the car. It was a pretty tight squeeze, with the cars I was trying to get in there.
Oddly, these condos were built around 1972-73, when the big car was still the standard by which all others were judged...and a '70's big car was noticeably bigger than a '67 Catalina or any DeSoto short of the long-wheelbase models. So you'd think they would have been built, with those bigger cars in mind?
One of my previous neighbors had a mid-70's Newport, that easily had a good 9-12 inches over my DeSoto or Catalina. He looked like he was there for the signing of the Ten Commandments as well. How he got that car in and out of that garage, I'll never know!