How about inside the spare tire? That is a spot the smugglers use. Alter the frame rails so they can be opened? Inside the headrests? I come from a bootlegging family on my mom's side. Can you imagine if my granddad had our modern cars back in the day? Not sure if they would haul more white lightnin', but they would sure do it FAST! Especially compared to his mid-30's hot rod Ford (he hauled booze from Missouri into Oklahoma after prohibition was repealed, but while Oklahoma was still dry - didn't need a tank because it was bottled stock in the trunk).