EMP should only effect computers. The series Future Weapons on the military channel did a special on EMP awhile back. There is an EMP test facility in New Mexico where they have a device that simulates an EMP attack by putting out several hundred kilovolts. The host drove a modern car under this device and it stopped the car dead. The car stopped running and would not start. However the lights, radio and power windows still worked. While the computers in the car were fried it obviously did not affect the battery or wiring.
I would think the 123chassis cars should be immune from EMP. Also, He should be worried about EMP because several countries can launch this kind of attack on us and it's not too difficult.