It's called cross talk, try it...We have a few cars with boxes that dont use cross talk either, I never understood why. They lite the top bulb of the faster car when the slower cars tree starts. Just ad the 1.00 to the box. Give it a try you may like it. You dont have to cross over to do it, incase you dont have a box with crossover capabilities. But to each his own.

On the blinder deal, just design something that works. We simply use the factory visor/extension in the car and some head movement to blind the tree.