Whoa, that's a big find right there. I don't think I need it anymore, but that should be sticky for any toyota driver wanting to install a guino.
My problem remains as I retire this project for the evening:
I rechecked the wiring, and resoldered a couple ground connections, but the display is still flickery at times, but stays solid if you don't touch anything, and I reconfigured the buttons the other way... I still don't quite know how tactile switches are configured, nor do I know if my switches are normally on/off. This was never specified in the plans, and i'm not sure if it even matters. I only have 2 leads from each of the switches in the circuit, and the circuit goes across the switch on a side where the pins are visible:
