The stock Subaru navigation system in most 2006-2009 (2010 for Tribeca) is a Kenwood 7" touch screen. This model has a particular annoyance. It locks the controls when the car is moving. So you are driving down the interstate and need food/gas/hospital you have to stop on the side of the road to allow your passenger to enter data into the touchscreen. Here is a simple fix that requires no computer hacking skills and no micro electronics talent. Any one with a piece of wire and a 10mm wrench can bypass the navigation lock out.
Find the navigation box. The Tribeca stashes it under the drivers seat. With the seat all the way forward you have easy access to the two 10mm bolts holding the shield in place.
Under the kick shield you find a couple of wires and a few plugs. The plug on the bottom right is where we will go.
Add a piece of wire from the second to the left pin on the bottom row to any ground point. The 10mm bolts are what I used.
Between the green (with black stripe) wire and the purple wire is my black heat shrink wire. I used a non-insulated crimp-on quick connect plug to help the wire fit snug.
On newer models you can check your success by entering the SECRET menu. Press the menu button and hold your finger on the top center of the screen (no buttons) for 10 seconds. This will open the diagnostics menus. The code to open this is 0412220. In the 'NAV' screen you should see 'PKB=ON'.
The only issue I have seen arise from this, has been you need to press the 'Start' button twice to begin navigation while driving. That's a big one right?
Side note: If you look at the second picture above, behind that blue wire is a green plug like a headphone jack. You can connect the Kenwood hands-free microphone in there and gain hands-free navigation as a bonus!
Disclaimer: It is dangerous to play with you navigation system and drive. Let your passenger do it. This could void your warranty if your Subi mechanics notice it.