Just to add my 2 cents, I've had the steelhorse in my X ever since I got it, to me, it looks better than stock. ( I believe I was the first )
Because of the size of the console, it was easy to make a mount for my laptop.. which I've been using for navigation with my GPS since last Christmas. I prefer a laptop, only because I can bring it with me out of the X... not sure how a real installed puter will work with our cold spells as well.
If I had a touch screen, I would mount it in a similar fashion as my laptop, it would resolve the present conflict with my screen and shifting.
Look at my page for ideas you can spin off from, if it helps
www.geocities.com/x_canuk/gps.html

Edit: I use Microsoft Streets & Trips.. super cheap, covers both sides of the border, and haven't been able to stump it yet for road navigation.