To follow-up my own message: I just happened to rent a Ford Focus for the weekend. It's a small, economical car with a decent interior. I was using the factory stereo in it and realized that the rotary volume controller would be excellent for the empeg. It is just the right size, has a rubberized feel, and a *very* satisfying mechanical 'click' when you turn it. It can also be pressed-in to select functions.

If anyone else gets a chance to look at the stereo in this car, let me know what you think of the controller.

-Oscar