Ad-hoc alarm systemCar alarm systems can cost hundreds of dollars and professional thieves are savvy about bypassing them, but with a little bit of clever MacGyvering, you can rig up an inexpensive and stealthy alarm system that many thieves may not even notice. You can run a wire from the hot side of your car's ignition circuit to a toggle switch, and another from the "on" side of that switch to a horn mounted under the hood. When you are ready to drive the car, you'll know to flip that switch to the "off" position so you can drive in peace, but a thief won't be aware of this system's existence. If someone tries to hotwire your car, the horn will sound, alerting you and your neighbors to their nefarious doings. This is a simple solution that will cost only a few dollars and a couple of hours of your time, but could save your vehicle from ending up on a shipping container or in a chop shop.Parking strategiesAnother way to protect your classic car from theft is to park it somewhere that makes it difficult for thieves to get to it or extract it. If you have another vehicle, parking it in a way that prevents thieves from driving or towing your classic away is a simple and cost-effective anti-theft strategy.If your car sits alone in your garage, stacking items behind and around it will add to the time thieves have to spend getting to your car and getting it off your property, and the added noise they make in the process might be enough to alert you to their presence and save your car from being stolen. Simpler strategies — like just locking your garage, alarming the door, or even removing the outside garage door handle — can also help keep your car (and tools) safe from theft. You may not always be able to keep intruders off your property, but sometimes just frustrating or delaying them for a while is enough to protect your beloved classic.