When you park, always roll the windows up tight, lock all doors, and take the keys with you. Never leave your car with the motor running, even if only for a minute to run into a store or your home. Never hide spare keys in a secret place or in a magnetic key box under the hood. Car thieves routinely check the visors and ash trays, and look under floor mats for keys. If you feel better with spare keys close at hand, carry them with you in separate locations.
Some thieves use tow trucks to take cars.
To avoid being towed by a thief, turn your wheels toward the curb and apply your emergency brake. Leave your car in gear or park. If you have a stick shift, put the gear into forward or reverse and apply the emergency brake. If you have a garage, use it. Lock both your car and the garage.