Though there's little you can do to stop a determined car thief, says convicted thief "John Smith," you can make your vehicle less vulnerable, if you:
Park it behind a fence, even if it's only a low chain-link fence across the driveway. "Thieves don't like to go inside a gate."
Park it near windows, even the windows of a neighbor's house. "A thief never knows who might hear a noise or be looking out."
Park near the entrance to entertainment areas and always in the light. Avoid secluded places.
Put emblems on your car saying "I'm a member of an auto club that pays a $500 reward for information about the theft of this car." "That turns a thief off."
Get yourself a dog. "A dog is my main enemy."
Install a good "shake alarm." The alarm sounds if the car is jiggled. Because the owner installs it the thief doesn't know where it is located. A thief can avoid a door alarm by crawling in the window. Some horn alarms can be disengaged by ripping out the horn wires.
As for private garages, he says, "If I wanted a car, a garage never stopped me." However, he says, it does keep your car out of sight of thieves searching for a particular model.