I have a 2006 X5 with Nav, no DSP.

I'm considering buying a new Android head unit. There seem to be 3 form factors - 7" screen with buttons, 9" screen that sits vertically and goes up to just underneath the center vents, and 10" widescreen, no buttons.

We it's he has all 3, Avin has the first and third, etc.

Any input on which form factor to choose? Why?

I am leaning to Avin, but will consider Seicane, etc.