While grounding may not be entirely necessary in some cases (still researching that), any openings will negate any protection provided by the vehicles body - ie windows are going to be a BIG problem.
Also, the wiring thoughout the vehicle acts as an antenna, channeling the EMP from exposed areas to more critical, and normally shielded, areas concentrating the pulse and causing damage.
I've found at least one example of where EMP was so strong in wiring that it welded them together!
__________________
If it moves, shoot it, if not push it, if it still doesn't move, use explosives.
Nothing happens in isolation - it's called "the butterfly effect"
Mors ante pudorem
|