I used a dedicated Magellan car GPS in the Grand Caravan (a.k.a. Frostbite One) for years, until I got a new iPhone and found that it made a better GPS than the dedicated unit. That worked pretty well for a while, until I upgraded my iPad mini to a 3G/LTE version and figured that a 7.9″ screen would make an even better GPS.
And boy howdy, does it ever.
Let me tell you that an iPad mini with a cellular data connection makes a ridiculously useful car computer. I use the iOttie dashboard mount, which is rock-solid. Most of the time, the iPad is in GPS mode via the MotionX GPS app. (Safety disclaimer: I only use the screen for navigation purposes and to switch music while I’m driving, not to browse the Intertubes or do Facebook updates at 65MPH on I-89.)
Other things I can do in the car now: stream Pandora to the car stereo, listen to my iTunes music or audiobooks, use the iPad as a dash cam via the rear-facing camera, look up stuff online (only while standing still, see above disclaimer), and basically do everything else I usually do on the iPhone, albeit on a much bigger and easier-to-use screen.
The iOttie mount is not only extremely sturdy, but also easy to operate. Getting the iPad in and out can be done with one hand because the little arms that secure it are spring-loaded and actuated when the back of the iPad is pushed into the mount. I hook up the iPad to the USB charger in the 12V socket because the GPS location services are really battery-hungry, and because it’s nice to arrive at your destination with the device fully charged.
It’s not as elegant as a built-in vehicle GPS/entertainment screen in the dash, but I highly doubt that any car manufacturer offers a factory solution that has more capabilities. And this carputer is detachable and goes from car to backpack in about three seconds.
This future: I like living in it.