https://techcrunch.com/2020/12/02/im-obsessed-with-the-ford-mustang-mach-e-physical-touchscreen-volume-knob/

The 2021 Ford Mustang Mach-E features a giant touchscreen, and at the bottom is a sizable knob for volume control. I love it. There, stuck on a touchscreen, is a physical knob. Twist it! Spin it! There’s even a resounding click as it twists. The knob works so much better than a touchscreen slider bar, and I implore other automakers to follow Ford’s lead. This knob is a surprisingly simple solution.

Under the knob are tiny strips that interact with the touchscreen as if it was touched by a finger. When the knob is twisted, these strips drag across the screen, tricking the system into thinking a human is controlling it. As far as I can tell, the knob itself is nothing more than a few pieces of plastic glued onto the screen.