[sarcasm]nah, just stick the magnet to the back of the truck and wire it! enclosures are for suckers![/sarcasm]Keep in mind that you might be able to physically fit all of the drivers back there, but regardless of quality, it will sound like garbage because each sub needs a calculated amount of airspace, which you cannot possibly provide in the back of a pickup truck.
Whether or not that is the case, that doesn't mean it is a viable idea. It's your prerogative, but speculating about it like this is rather pointless. Measure the space, and you'll know how many will "fit". Simple as that.Like I said I like a challenge. And if theyre in a sealed enclosure I think I couldnfitnem