You don't need to own a car in the Cayo District of Belize, but it's convenient, especially if you’re going to live here full time. The reason is that if you want to go out in the weekends, go explore a different area, do something else with friends, it’s best to have your own car. The same would be true if you live 2 or 3 miles out of town, because you would need a car to go to the bank, post office, restaurants, market, etc. You could go with taxis but, then you'd always be depending on somebody else for your ride.
The Cayo area in general is a low-density, spread-out place. Maybe while you’re at a grocery store, you may think "Whoops. I need tomatoes for my pizza and they don't have the branded one,” which means that you may have to go back to Santa Elena, which is a lot easier to do if you have a car. Things are kind of just spread out here. Sometimes you walk to get some eggs at the chicken place, but if you want to get your chicken meat, you have to drive there.
When you do your errands it's not like you would just go to just one place. There's multiple places you would go, and that's why it would be better to have a car. You would want to have that freedom to check out and go to other places-- stores, a party, restaurants, etc.
(A road that leads to a farm in the Cayo district, Belize, pcitured.)