My cousin had an excellent solution many years ago when he had some muscle cars. Remember those floor mounted headlight dimmer switches in vehicles built in the 70s and earlier? Before they started putting them on the very complex turn signal stalk. Those are still common items in the auto parts store.
Mount one of those on the floor underneath some carpet in series with the starter wire as operated by the ignition key. I just hit the switch once to start my vehicle and once it's running hit it again.
Now if you need some work done on the vehicle just leave the switch on and don't tell the mechanic. They'll never know. Same with valet parking.
A friend who is a criminal defense lawyer who makes much of his living from Legal Aid tells me that the standard druggie won't spend more than 3 extra seconds trying to get a vehicle going. Any problems and they're on to the next one. Sure your door, window and/or ignition lock will be busted. Oh well, better than the hassle of locating your vehicle days later in whatever shape in might be.