check out this guys kits. ..... .. though the inputs are way different.

Cool! Different, but that's the metaphor I'm aiming for. I might have to e-mail him. I would even pay someone for some of these bits so long as I learn something along the way. Being voltage driven, his light up only 1 LED, I think. For my speed up/slow down, what I want is something that you can pick up in peripheral vision (I'm even thinking quasi-HUD via reflection off a windshield film strip) where the green/red bars grow in an obvious way. Our driver display had an ahead/behind bar on the VFD, but I had to look right at it to decode what it was telling me. Better to look at the road!

I never even thought about the fact that it could be a great (couple) activity with the navigator and driver! =]

Yes, so long as one member of the couple is immune to car-sickness or has good results with Dramamine or a patch!!

Back to electronics... this looks like a fabulous idea. I wonder if you could actually use an empeg somewhere in the chain?

I gave that a good, hard, think but decided I would leave more options open if I went with a separate board/CPU/interfaces. I was also concerned about contention issues. It would not take much (especially at very high or low CASTs) to have your calculations get way off! A super-duper version of this system (even further beyond my skills!!) might even offload clocking and calcs to a 2nd CPU or ASIC.