And yet I frequently see (in New Zealand), properties with oversized double garages (often built to fit oversized American vehicles) and driveways that take up half the land on the property. Cars use a huge amount of space in roads, carparks, garages, and are responsible for pushing things further and further away from the home. And then somehow cars are seen as the solution for the very problems they create. There's plenty of real world evidence that there are better ways to solve this.

I don't think cars are responsible for bigger backyards at all. The size of the average property where I live only seems to be shrinking as the roads get more and more congested.