okay, done being a wise guy. When I lived in Brooklyn, I had a double set of features put onto my beloved Mustang - a keypad that killed the ignition coil (so it would turn over, but not start) and a medeco or similar lock - one press - locked the hood. pressed all the way in, complete starter disable. I rarely did that, was a pain in the neck, so just locked hood.
the keypad was a breeze - i could put it into valet mode, or just hit the 4 numbers and unlock the starter. it took like 2 seconds and was a second nature habit after a few days. i think it did show discoloration where i hit the keys (my prior home door lock had the feature where you had to press 2 random keys it would light up to help you keep the keypad uniform)
i'm not sure how annoying or simple the pin unlock is, i saw it on my buddy's when i played with his car for a minute.
maybe there's an easy way to activate the pin lock, or maybe there's a way to do it or try to remember, when you're in a potential dangerous situation.
i'm also wondering now, if the phone is close enough, can someone else unlock your car?
can you be at a kid's soccer game, etc. and if near the car, someone can get into it? drive away?
suddenly this pin idea is sounding better and better....