House is locked, but the car...
Our double-car garage can only hold one car when it's a sizeable crossover-type SUV, plus multiple bikes/toys, lawnmower, snowblower, and various manual implements. (The garage "car" is also newer, nicer, and leased; naturally, the missus gets it to take the kids to school and run errands).
The older (same model), owned-outright car, my daily driver, sits on the driveway instead. Both I and the missus have left it unlocked overnight for various reasons, but usually due to unloading something and the having hands too full to use the key fob to lock up. It is a testament to the safety of our neighborhood that it hasn't been taken yet!
(At least if I want to pre-start it, missus gave me a remote start unit as a gift for letting her have the leased one. Locked or not, without the key it will shut down as soon as you touch the brake or mess with the wiring -- fail-safe by law.)