Hi Brian,
I have a 3/4 inch plywood shelf that sits on the tub edges of my TJ, secured through the bolt holes used for the hard top. It has cut-outs at the back for the roll cage and seat belt squares and covers almost all of the tub. There are also anchor points where the bolts are to strap stuff down but I don't usually bother.
that there's a great idea, i'll bet that would work well in my situation (money, time-not enough of either...lol)
It turns out the shelf is just high enough so a coleman extreme cooler and one of those square blue 5 gallon water jugs can slide underneath.
You might be able put a similar shelf behind the rear seat in an Unlimited but I've never seen one close up so I don't have a feel for how much space you have to play with back there. Do your kids have legs that need space yet or can you put lots of stuff on the floor between the front and back seats?
there's quite a bit of space, maybe 2-2.5' x 3.5'.....and yeah the space between the front and back seats are up for grabs as far as
storage...didn't even think of that. i also want to use the fenderwells somehow...either with a jerry can holder on each side(water) or maybe sidesaddle type soft bags.
I also have a roof box on the rack. It doesn't seem to affect the gas mileage compared with the rack and no roof box. what would you say your losses were once you had the roof rack up there? 1-2mpg?
As goodtimes says the security aspect is a plus, but I found the best thing is its possible to slide the big things like cooler, lawn chairs, etc in and out without having to move anything around.
Cheers,
Graham