modify the position of parts & traces to be a little cleaner
move LED's away from the top edge of the board
remove 20V zener
replace 5V zener with 4.7V zener (hard to find 5V zeners)
merge 10K + 22K into a single 30K resistor
clean up traces & remove lots of vias
Add 'mode' button
Add means to detect Very Low Fuel on later models
Move +12V back to ignition