The iPhone is more than capable of acting as your dedicated GPS device. You are just going to have to install Google Maps or other GPS apps that could actually help you get to your destination (unlike the flawed Apple Maps). In order to keep your phone stable and safe in your car, you are going to need one of these dashboard mounts too:
iOttie Easy Flex2 Windshield Dashboard Car Mount: this is a one touch mounting system that locks and releases your device fast. Its extra-large suction cup guarantees the mount will stay put on most smooth surfaces.
iKross 3in1 Car Vehicle Windshield / Dashboard: a windshield, air vent, and dashboard mount for the iPhone 5. Its arm absorbs vibration and provide stable viewing platform.
i.Trek ME-USDM Universal Dashboard Mount: its built-in bracket fits up to 5″ screen devices. The design is compact and works great for vehicles that can’t handle windshield mounts.
Ppyple car dashboard holder mount: this smartphone provides support for your smartphone in portrait and landscape modes. It can rotate 360 degrees. It is compatible with popular Android smartphones too.
TaoTronics TT-SH02 Car Windshield & Dashboard Mount: useful for those of you who need both a windshield and dashboard mount for your iPhone 5. It works for phones and cases 1.97″ – 3.94″ wide. It has a large suction mount for maximum stability.
These iPhone 5 mounts let you install your phone on your dashboard and use it as your GPS device. They keep your phone protected as you drive.