On the Mazda 3's, the automatic shift knob doesn't have a button. You just unscrew the knob to remove it, but the thread on the shifter is small. I was looking at getting another knob and you need one with the spacer so it doesn't move around. I still haven't bought one because the ones that take a allen wrench to put them on always seem to loosen over time. Wish I could find a screw on one.