[Tomdarkness]

The reason I have it built-in is it integrates with the head-up display meaning I don't have to take my eye off the road to see directions.

[kctess5]

This. My mom's BMW has a really useful navigation display on the HUD. It also shows your speed. These two things mean you basically never have to look down from the window. Definitely comes in handy, especially in stressful driving scenarios.