Not actually familiar with that particular vehicle, but, surely there are cables that pass through
the firewall into the passenger compartment. If so, there is usually a rubber boot where they
are bundled up and pass through the opening. And in a lot of American made cars, there is enough
room to slip some fairly large wires in alongside those cables going thru the rubber boot.
Otherwise, you will have to find a spot to drill a hole. (and add a rubber boot to prevent chaffing
and shorting of your power cables)
good luck
james
WD5GWY