Car theft has traditionally been the province of the lower class of thief. Typically a car is stolen to sell for parts, or as a target of opportunity for a joyride or a quick get away. In an action-adventure game though, there are plenty of situations where stealing a car is a short term goal for the players. It may be to use on a job, or as a way to move around in a vehicle that isn't known to their enemies. There are also things you can do to an enemy or mark's car that may be useful.

Stealing the Car

Any car manufactured after 1998 in the U.S. (or manufactured for sale here) is required to have an immobilizer device. This is a system that interacts with an RFID chip in a key or key fob, and prevents the car from starting unless a valid chip is present. Cars will typically recognize only a small set of RFIDs, so that even if two people have matching keys for a Honda Accord, once cannot be used to start the other car, because the chip in the matching key has not been assigned to the car.

On older cars, these sorts of systems could be bypassed by a little bit of creative wiring on the steering column (in fact on many cheaper cars, this was a recommended practice for legitimate owners, because older systems were prone to failure). Once the anti-theft system was bypassed, a screwdriver in the ignition switch and you had a new car. On cars with more modern systems, the immobilizer device is tied directly to the engine computer, and if the computer says the car isn't going, the car isn't going.

To steal a car very easily, all you need to do is sit down next to your target in a coffee shop, open up your computer, and start checking your email. Of course, while you're checking your email you've got an RFID antennae in your pocket, hooked up to the computer. Within 15 minutes your computer can run through all of the possible signals that would trigger a response from the key. When you replay that signal to the car, it will let you start the car up even with your screwdriver in the ignition switch. On high end vehicles like the Lincoln Town Car, it will even unlock the doors for you as you approach.

The newest systems are somewhat more difficult to attack. They use features such as rotating ids and encrypted communications to transmit their keys. There aren't presently well-known attacks against devices, but a capable attack would make a great mcguffin for an adventure.

Altering the Car

The real fun kicks in when you're altering the functioning of the car. Pretty much all cars built since 1996 are run by a computer, which controls at least the firing of the spark plugs. If you can control that computer, you can control how that car runs.

On a newer car, with the built in navigation systems and complete control over pretty much everything in the car, if you control the computer you control everything. Not just will it run but how fast it will run, will the doors open, what speed will the driver think it's going, and where will the navigation system tell them that they are going.

If your enemy is navigating in unfamiliar territory, chances are very good that they are using one of the satellite navigation systems. Compromise the navigation system and it's fairly easy to redirect them to where you want them. This could be an ambush, or just someplace where they aren't in your way.

You can also throw off their timing or cause unfortunate involvements with law enforcement. If you alter the speedometer to show a different speed than the actual speed, you can put them behind in their time. You can also make them think that they are running slower than they think they are. Misunderstandings about speed are known to cause flashing lights in the rear view mirror, which in turn cause delays and possibly searches for contraband.

Malfunctions can be caused by altering the engine timing. That would make the engine run rough or stall. A stall is not particularly suspicious, letting you delay your enemies without tipping them off that you're doing it. It works best if you can trip that feature after the enemy is on the road and arranging alternate transportation will be difficult.

The trick will be getting into the computer. Very modern cars have powerful computers and bluetooth networking. Pull up next to their car and a good hacker can do bad things. An older car will need some device installed which will give the hacker access. The computer in a car has a specialized connector that can be hooked up to a personal computer, which would let you alter settings such as transmission shift points or engine timing. A radio receiver wired in would work as well, although when the mechanic looks at it he'll find the new device, even if he doesn't know what it is.

Conclusion

Playing with cars in game can be a lot of fun. I live near Flint, Michigan, where General Motors got its start, so cars are kind of in the blood. Cars aren't a passive item in our game world, but something we're always aware of. Control the cars in a modern setting, you control the world. If you want to work that same world view into your game and you can have a lot of fun being bad mother hackers.