I don't want to offend you, but that sounds crazy. If you're only going to live there for 3 months, you don't need a garage. Or, if you really need it, you can just rent it, which will be a hundred times cheaper. Some people don't build a garage in a house they're going to live in for years or even their whole lives. My parents didn't have one for 10 years after moving in when my dad decided to build one. And you'd be surprised to learn that they didn't even keep cars inside. It was a matter of habit. Anyway, I suggest you keep your car outside, if at all possible. However, if you really need a garage, you can look for renting one of their siesta key beach house rentals.