Biggest concern while replacing my audio system with Nexus 7

Hey guys, I'm a new Armada owner. My Armada came with a Chinese touchscreen navigation system with DVD player and a 2nd screen for the rear passengers. I've been planning to replace it with a Nexus 7, but my concern is how to use the 2nd screen with it. I have seen installs where the stock stereo is relocated to the glove box but it's very difficult to relocate the large double DIN set.

Any ideas about this issue will be highly appreciated