idea:
When driver in a car: press W/S Hold it and scroll mouse wheel to incrementially increase decrease the speed. E Full speed and Q slow could still be applied if needed. When not pressing W/S and scrolling the action menu appears like normal.
When pressing W/S and scrolling the mouse wheel, the button remebers the last speed. so when you brake then press W/S again to drive forward/backward the last set speed is used for it.
This would be an easy way to get more than the 3 speeds! (Q, W, E)