Are you looking for a car dashboard or mount that works with the Nexus 7 in landscape mode? I use Arkon SM517 Windshield Mount for 7-Inch tablets which I bought from Amazon and NavFree USA app for the tablet. That works great in my car for navigation with gps.
Arkon's SM517 Windshield mount is a perfect way to mount your 7-Inch Tablet for use as a GPS device or for watching movies. It fits the Nexus 7 perfectly. Cheap price and good quality. It is strong enough to hold the tablet securely. Easily adjust the viewing angles. Highly recommended and no complaints.