Hmmm. You will most likely just have to run it along the side of the bar. As long as you do not raise the headrest, no one will be able to see it.
On another note, I have the Directed Electronics Magnum specific headrest on order. Should be here any day. I thought about just putting the monitors into the stock headrest, but they have such a forward "lean" to them. Just looks like the monitor would be hard to see at that angle. The DEI ones come in the color/upholstery of your specified interior, and run $109.95 each. I already had the 7" monitors out of my Nissan DEI headrest, so I only had to buy the empty headrest.
Post pics when you are done.