I don't think this https://www.empshield.com device that costs $389.00 would work to keep the electro magnetic pulse (EMP) of nuclear explosions from frying the electronics on a vehicle. The only way the device might work is if the negative line was connected to a 10 foot long copper grounding rod.

Having electronics grounded and unplugged inside a Farady Cage is the only sure way to protect from a nuclear blast EMP.

I would rather have a vehicle with a carb and ignition points or a diesel pickup with totally mechanical fuel injection. Even then EMP could take out the diodes in the alternator.

We had better plan on doing lots of walking when a nuclear war starts.

“I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.”
― Albert Einstein