Of course this is the part I say DO AT OWN RISK.
This was easier then I thought, I'd give it a 6 out of 10 on the DIY scale.
Of course take your time!!!!
-----Parts list-----
2- XO Vision 7" universal monitors
1- box of 1 1/2" self tapping screws
1- utility knife
4-5 hours of wife/kids free time in the garage
I used the rear headrests as they are a little bigger. You could use the fronts if the monitor was smaller. But I'd recommend the rears either way.
First off get the template that came with the monitors. Measure and use visual with template to get the monitor where you want it and centered. I used mostly visual since it's hard to measure this weird headrest shape.
Once you get it where you want it use a fine tip marker to trace the outline. Then cut the material from corner to corner, leaving the material in place

Now peel back the material and tape it out of the way. I would add to tape the edges around hole so your tools don't cut into cloth (I found out the hard way, but lucky for me it doesn't show when finished)

Now here I used my dremel to hollow out the foam. The bit for tile (I think) worked great. But be careful this bit will go through cloth as fast as foam!

Now while cutting the foam I would say cut a little - check fit, cut a little -check fit / repeat. If you cut too far it's not that big of deal, you just stick a cut rectangle piece of cardboard or two till your good. But if you take your time and check fit every once in a while you should be good to go. Also go about 1/8" past the edges to account for the cloth.

Now that the plate fits take a small long rod (I used a metal 6" section of coat hanger) and poke around to find the metal rods that go up into the headrest and loops back down. Once you know where they are simply use the self taping screw and secure the mounting plate. The picture only shows 2 screws but I used 4 (one in each corner). Next I used a 1/2" hole saw dead bottom center and drill a hole about an inch. If you stick your finger up the cloth crack on the bottom you can fell the thickness, this is to put the wire through.

Now stick the monitor in the mount and done

Now to fish the wire through the seat I removed the back metal rings holding the cloth together at the bottom. Stick a string (or old wire if you have no sting as I did) in through the side of the headrest mount. Tie and tape it on and pull it through. The big s-video end is hard to get through so reach up from bottom to help guide it because you don't want to pull to hard from top and snap the wire.

now take off the string and plug in the new headrest

Tape that connection up real good with electrical tape so it wont get disconnected or touch metal in seat and shove it back through

Thats one done now. Repeat steps for second headrest.
After you get both done open trunk get a cold beer and gaze at your accomplishment