You are both way overthinking this, and way underthinking this. Ever watch in a big parking lot when a car alarm goes off? Absolutely NOTHING happens. Nobody looks!!!! Nobody investigates!!! Everybody just assumes it's an accidental alarm trip!!!!
There was a case documented here (if the facts are correct) where some guys race car (and trailer I think?) was stolen out of his carport, AND THE THIEVES MOVED one of his other rigs to get it out. This was right next door to his house as he was asleep. Thieves don't have to be "sneaky."
They pull up on a busy street, they look like mechanics or repo guys. Unless you the owner, catch 'em in the act, or have it alarmed.