Rigging a mecanum wheel (Different modifiers to different drivers)


So Im learning the basics of rigging a car wheel, and it works fine for rigging the wheel to rotate when the main body is going backwards and forwards (x-axis). It does also work to some extent to add drivers for movement when the body moves sideways (y-axis) and rotates (z-axis)

However, for mecanum wheels I would like the wheels on one side to rotate one way when going sideways and the other side to rotate the other way. I would also like the wheels to spin way faster when rotating around the z-axis then what they do now. The problem is that the modifiers for drivers seems to work on all of them at the same time, when I would like to have one modifier per driver (so that I can change the values in the ‘Generator’ modifier)
Is this doable?

I suppose this is the kind of motion you like to see?

To reverse wheel direction give each wheel an integer property and call that property as a coefficient for wheel speed in the driver, i.e. the property switches between 1,0, and -1 so multiplying the speed by this will either move forward stop or reverse.

That sounds interesting, but how do I do that?
If you mean the ‘generator’ modifier this unfortunately affect all drivers the same, so that I can’t have two wheels working in different ways.