Empress make a four man vehicle crew set. It is intended to be used to "rescale" Airfix 1/48 scale British vehicles.
Thought they would work with the Empress WW2 American jeep.
here is the contents of the pack.
Here are two of the figures perched on the seats of the Jeep.
A side view showing how well they fit.
Crooked Dice are doing a Post Apocalypse range and they have crew figures which might also be of use.