[dogma1138]

The car wasn't "hacked" they are reading the canbus and using that data as an input for the controls of a game that runs on a separate computer.

This isn't different than using a USB steering wheel and pedals setup.

It also requires no "hacking" just access to the canbus which can be accessed in most cars through an interface under the steering wheel or in the glovebox.

As long as your car is fairly new all the driver inputs will be transmitted over the canbus.