I take your point on speed when not in any gear - didn't think of that X-). A basic traction control system could be as simple as comparing the driven axle speed with the undriven one and killing the fuel or ignition if the driven one gets too much ahead - it'd be not unlike have a PWM internal combustion engine. Appreciate that's 50% more transducer counting though.
The idea of the over temp (or over/under anything else) would be the warning would be coordinated with the display - the buzzer goes off and the (multifunction) screen shows the related info. It ties in with the idea of the analogues "auto promoting" themselves when they have something new to say. You could have AFR displayed as default, for example, then when the coolant temp notches up another bar on the gauge it automatically replaces AFR on the display for a while, chuck in a blinking backlight so you don't miss it.
A time stamp from a clock could also be useful if you are logging data off your mpg gauge.
Appreciate Rallyduino has a different appeal, just wondered how easy it would be to splice the 2 together to run on the same hardware since so much of it could be the same?
Boy it's easy to dream up these ideas when you haven't got a clue of how to make them happen
