This brings to mind a pair of related notes / general rules; 1. no matter how paranoid it might make you, it's best to not do illegal drugs behind a locked door, (or at least don't bolt it, as above.) and 2. If you feel you're in a shady neighborhood, etc., go ahead and lock your car doors, but on the highway, leave them all unlocked. The door lock in cars merely disables the opener - it does not provide additional rigidity, security, etc., but it will markedly slow down any efforts to extricate you if you get smashed up.