Perhaps the right scroll wheel could control the zoom in and out of the map if it is highlighted on the 17″ display. It is pretty common to zoom in or out based on what you need to see and it would be quicker and safer to have this as an option on the wheel rather than only controlled on the screen.
Pinch to zoom was added in v5.8, and in v10, voice controls such as “Zoom In” or “Zoom Out” were added. In addition, some automatic zooming occurs based on speed.
Really would be nice if the scroll wheel was "active" to what ever app was up and running on the 17" screen. If it was the nav system, you could zoom, scroll, etc. If it was music, you could fast forward, mute, volume up & down.
Phone, you can scroll up & down the contact list, enter call / mute.
Personally, it is dangerous to take your eyes of the road to look at the screen, let alone your hand off the wheel, just to touch the screen!
It is a computer first and foremost, a car second.
Auto-zoom based on speed and nearness to navigation points would be good too. Navigation points are aided by the speedometer display so perhaps that's less important, but speed-sensitive auto-zoom would save some manual fiddling.