I installed a toggle switch to turn on the radio, a toggle switch to turn on the computer and fuel pump/injection, and a push button starter switch. I used a 40 amp auxillary headlight relay to reduce the current through the computer power switch, the stereo toggle is a 20A switch, and the starter button is a heavy duty one, so no relay was needed there.
Here are the switches exposed; the start button is where the cigarette lighter should be.
I had a couple of people ask how the wiring is done, and if you could do it differently, so here you go! More details are on my blog.
