Still missing something - the garage would have to be on your private property, not visible from public property, and the only way he could check for you is if he entered your property and tried to get into your garage.
On the contrary, I would say that this is a garage you rent on a public space. The internet is open and I can do requests to any server. If you don't want your system to answer me, make sure it does not.
If I am in front of an ATM on the public street, it doesn't give me money without authorization. Make sure your server does the same.
Streets are generally open. My house is on a public street - that doesn't entitle anyone to attempt to operate my garage door, let alone exploit a security vulnerability in its software to gain access. That's just trespassing.