I've owned a car in a city, a high density suburb, and a low density suburb (all USA). I had the one non-alarmed car as a teenager in the low density suburb.

I've owned a car in a city, a high density suburb, and a low density suburb (all USA). I had the one non-alarmed car as a teenager in the low density suburb. It was broken into in the quiet residential driveway. In the city and the high density suburb, I have only ever had false alarms. Maybe the answer is to give the user the option to arm the alarm or not when exiting, with equal friction (i.e. separate "lock" and "lock+arm" buttons on both the door and the fob).