Random bits of random vehicles should be Evil and want to kill you. Most vehicles in the world are, obviously, in no fit state to attack, and many parts have limited ability to cause harm, but they should probably have a range of influence, maybe they can control any part on their own tile and random items from adjacent tiles? It would be pretty cool if after installing the wrong part, or installing a part near the wrong part, would cause the handbrake to slip when you are walking in front of your rollingdeathfortress, or maybe your doors tend to swing closed rather abruptly, or your airbags trigger when you are trying to avoid that minefield(bonus suggestion, airbags that blind the survivor), or maybe your seatbelts start contricting, or maybe that one wheel gets a mind of its own whenever you drive near a tree…
Perhaps you can appease them by driving over N.P.C.s at precisely the stroke of midnight and then they would use their powers for good evil instead of other evil…
