At least they made the effort!
In a car, a rotary knob is ergonomically wonderful
- it is in one location, so you can find it
- once you grab it, you can hold onto it during adjustment, even in a moving car
- you can increase or decrease large or small amounts quickly and accurately
It's unfortunate that tesla is going the opposite direction with respect to ergonomics (touch controls on the moving steering wheel for turn signals, gah)
Unless they have a ton of resistance (old school cable actuated HVAC) or are massive (typical Honda HVAC) rotary knobs suck for adjustment when moving. You want discrete up/down buttons (preferably ones that feel different) and enough dead space around them that the user has something to touch to anchor their hand. We've all sent the volume flying on a radio with a knob.
Are you talking about brushing the knob somehow?
Better than a touch screen, definitely, but worse than discrete up/down buttons
Sometimes - I don't know how many current model cars have them - they have dedicated up/down buttons that nevertheless are apparently capacitive touch operated. I remember the Buick Regal of a few years ago being like that, and I think I remember pictures of Cadillacs that looked similar.