That doesn't seem enough to prevent you from parking two cars in the garage, or at least one car and keep the other car in the driveway.
Fair is where you go on rides and eat cotton candy. Has nothing to do with laws or codes. You have the option of refusing to comply and go to court to fight it. Keep in mind that you are likely to have to spend lots of money to take it to the appellate level because your local court is likely to just rubber stamp it.
But do they also park one or more of their cars inside the garage along with the storage?
If storage is incidental to parking cars, that's OK.
If storage prevents cars from being parked in the building, then that's the issue for the code enforcement.

