:)))))))
All of the car electronics is rigorously tested for severe EMI. The tests are performed at the module level and at the vehicle level. IIRC the EMI up to 400 V/m @ 3 GHz should not influence the normal operation of the critical systems, and should not inflict any damage to non-critical systems. So, it is probably easier to cook the brains of the driver (if he has any) then to destroy any of the electronics by EMP.
Vladimir Vassilevsky DSP and Mixed Signal Design Consultant