If you have a portable GPS for emergency backup, or if you use it in your airplane for its terrain awareness or for receiving satellite weather, then your commuting time in your car can be put to good use. Even if you have the road database, it can be more helpful to stick with the aviation software for practice-especially on your regular commuting route where you need no navigation guidance.
Buying an extra dashboard or windshield suction-cup mount for the car is helpful, especially if you are able to configure your GPS in roughly the same location as you have it in your airplane.
