[m463]

I've used these such as bmw idrive and I think it takes far more attention to navigate menus using a wheel than either dedicated function buttons or a touch what you want touchscreen. Selecting a nav address is kill-me-now tedious.

I tried a nissan with nav and it had a pretty useful mixture of the two. It had dedicated function buttons for say radio or map or volume up/down/power (most duplicated on the steering wheel), but the touchscreen was used when that made sense, like selecting a nav destination from a list, or typing a destination with the on-screen keyboard (allowed when stopped only).