I'm don't think you need any buttons. They have given me a VW Touareg as a hire car and that has ACC and it is all controlled from the screen. True its not as easy as the BMW but works great. In fact I've been very impressed with the VW as it is linked into the traffic sign recognition and the sat nav so it knows when a roundabout or bend is approaching and slows down and it automatically adjusts to the road sign speed limits.
Here is the french link
https://www.bmw-connecteddrive.fr/ap...#/portal/store