fantastic ideas for continueed evolution of this project!
I like the idea of a button that stays on the players available hand and taps against the cab. Could you make this bluetooth to avoid wires to the left side controller?
Then the player could easily wire up and wear a belt batter pack to power the blue tooth device.
Alternate idea is another battery pack that goes on the glass and extends the regular cab button and brings an extra button to control the device (similar to what ben and I devised originally but using the weight again to hold it in place.
Last thing >> I would really like one of these if you get around to making them. I woudl be happy to purchase one. Keep that in mind as it may help costs to build 2 in place of one.