Your 90 anything will not be EMP proof... too many electronics.
A Faraday Cage must be solid conductor or have holes smaller than the frequency of the impulse/discharge it is trying to protect you from. For and EMP solid is best as the range of frequencies are very wide ranging. Expanded steel will do nothing to protect you in an EMP.
Think pre-1978, pre-emmissions, pre-electronic anything.
Even if you get a pre-everything vehicle you can still melt a point condenser, short and alternator and/or starter. Sending units can/will also be effected like fuel guage, temp, etc.