Message from 2021
This post is pretty old! Opinions and technical information in it are almost certainly oudated. Commands and configurations will probably not work. Consider the age of the content before putting any of it into practice.
An article at everything2 gives away the long code needed to guarantee entry into one of those luxury cars that has the buttons on the door. Maybe some of these cars time you out after a few failed attempts, but really I’ve never been a luxury car aficionado so you won’t get a definitive answer either way here.