I learned from a guy on a ski lift, a couple years ago, that he sleeps in his JKU at a state park a few miles away when he goes skiing. He told me that a twin mattress would fit in the back of a Wrangler if the front seats were move all the way forward. This is not a secret, but it was news to me.

I had a couple old 8" mattresses in my attic, so I gave it a try on a quick trip with my two young kids (7 & 9 years-old).
Here's what I learned:
It was very comfortable.
There's plenty of room for 2 medium sized adults.
It's tight for 3, even when two of them are half sized.
The mattress needed to be trimmed to fit around the center consul.
When sleeping to one side of the center consul, it was easy to fall into the ~10" space between the mattress and doors.
The mattress picked up every leaf, twig, and speck of dirt like a magnet.
The back seats could be used if the mattress was rolled tightly.
This blocked the rear window and left little space for gear.
The mattress was a bit unwieldy given its size.

Here's what I did:
I used two mattresses, cut into 3 sections -
One mattress was laid in sideways and cut to fit from door to door.
It was then trimmed to fit around the center consul just behind the front seats.
It was then cut into 2 pieces to roughly match the 60/40 split of the seats.







The left over foam was too small to fill the remaining cargo space in the back.
I had the luxury of a second mattress to use for this.
The foam was trimmed a bit here and there to fit the space better and to fit around a jump seat that I have in the back of my JKU.
Finally, my wife's friend covered them with black canvas fabric.







I still use a full sized fitted sheet to cover them when I sleep.
Individually, the 3 pieces are very manageable.
They don't attract leaves and dirt as readily.
They are modular, I can use just 2 of them when I'm alone which allows more space for gear and the driver seat can be left in its normal position.







The 3 pieces stack neatly behind the second row without blocking the windows.







Biggest plus: It's so comfortable, my wife asked when we're going camping next.

 

Nice!!!

 

Awesome job, it actually looks pretty inviting. Threads like these really make me miss my JKU and all of the space capability it had...

 

I did something like this for my jeep for when we go to the drive in to watch movies with the top down. Kido loves it and it nice to look at the stars

 

someone has this legit air mattress that fits a round console. here's the link
https://www.kickstarter.com/projects...-a-jeep-wrangl

 

I'll never do air again, hole in the mattress will ruin your trip!

 

Besides the xprite (not thick enough) does anyone make a foldable mattress (not air) that can be tucked under the rear seat of a JKU but then unfolded to sleep on?

Preferably 4" thick or more, when opened and ready to lay on.

 

Gosh, that is asking a lot. I used to use 4" egg crate foam that worked pretty good, but there was no way in hell that could fit under back seat. in fact, it pretty much took up the whole back seat once rolled up.