"The computer systems used to control modern cars are very vulnerable to attack, say experts. An investigation by security researchers found the systems to be "fragile" and easily subverted. The researchers showed how to kill a car engine remotely, turn off the brakes so the car would not stop and make instruments give false readings. Despite their success, the team said it would be hard for malicious attackers to reproduce their work. "
"The researchers concentrated their attacks on the electronic control units (ECUs)scattered throughout modern vehicles which oversee the workings of many car components. It is thought that modern vehicles have about 100 megabytes of binary code spread across up to 70 ECUs. "