The Inrix Navigation App has recently been updated several times but it still can't be viewed on the SYNC MFT 8in screen. As w1kedz said above, Ford restricts the ability to push video from peripheral sources onto the MFT screen while in motion.
If someone designs a "LockPick" for defeating this then we may have something.
The audio from the Inrix App will go through the MFT audio system so you do get loud voice directions but video is restricted to your source.
The issue with peripheral electronics inside a vehicle not securely attached is a significant safety concern too.
I recently watched some video of some crash testing where they wanted to see what happens inside a Police vehicle with all the extra electronics mounted inside.
I was amazed at how the suction cup GPS devices, Satellite radios, Smartphones, and radar units all instantly came unattached and flew around the inside of the vehicle. The vehicles had crash test dummies inside with sensors and the feedback was that these flying objects often contacted the dummies with fatal blows, especially to the head.
So please make sure you secure your electronic peripherals, especially if your trying to do a cost effective DVD system for the kids.