Sometimes when driving alone you get bored. Why not add a buddy voice? It's more than just a voice:
1. It can have different personas
2. it continues to give road instructions, but it also plays road games with the driver: I Spy, Counting Cars, etc. It can use the camera to see things and the voice command to communicate. t tells jokes, sings along to songs, etc.

It's like a navigator who's your bestie.