Push a Big Red Button & start the engine, just like classics of yore. Gives you something to do with that unsightly lighter hole, besides raise a stink, getting cancer, or powering an accessory that dangles on your knee (Latter for M1 only).
There have been several installations documented on the net, and mine most closely follows that done by Adam Wolf, who installed the button from a Honda S2000. I found one made by Arcolectric . I think mine is a C7000 AF BR. With a 28 mm diameter, it fits right in the lighter hole. You'll also notice I installed mine on the ground rather than the power side.
Assuming that, like me, you already have a couple drawers full of wire and connectors, the only other thing you need to get is a Single-Pole, Double-Throw (SPDT) relay and harness capable of conducting 30 amps. The relay and harness should be available at a local car audio installer (I got mine from the back room at a Best Buy); your local Radio Shack will probably not have them in stock.
Warning- look at the pin numbers on your relay! Don't assume they are in the same places as on mine, which is a Bosch. Most manufacturers use the same positions as Bosch, but for some reason Hella moves the pins around, even though they could plug into the same socket! So check, just to be sure, & go by the number, not the position.
The first step in this install is to read & reread this article and Adam Wolf's, cited above. You should also check those by Keith Tanner and Sean Archer ; Sean converted the hazard switch to this function, great idea, especially for M2's. And Cliff Knight's page for lots of relevant electrical info. Next is to ask yourself how comfortable you are hacking away at the wiring that starts your car. If this makes you a bit queasy, you probably should pass! If not, disconnect the battery ground, remove the panel under the steering column, and find the 6-pin, thick-wire connector under the starter switch, and the 2-pin, thin wire connector forward of the switch. If you can't, or your back starts complaining too much, put it all back together & go for a drive. Otherwise, stick a needle-nose pliers into the lighter, and start gently pulling and turning. It should come out after a minute's work, a bit mangled. Gently pull off the lighter's 2-wire connector.
Next, unplug the 6-pin connector. Note the black/red IG2 wire and the black/blue ST wire (these colors apply to M1's, and differ for M2's). Unwrap the tape around the wire bundle back a few inches from the connector. You may want to clip a couple of the zip-ties to ease access.
Now for the big decision - either cutting the ST & IG2 wires per Adam's write-up, or trying to pull the connectors out of the backshell per Keith's.
I got lazy & chose the easier-but-not-reversible-to OEM-condition cut. I'd recommend doing it Keith's no-cut way here, easing the B/R out of the starter switch IG2 & connecting it to the relay's 87a. Then make a new connection from relay 30 to the starter switch IG2 with 10 or 12g wire. Same way with the Black/Blue - ease it out from st, & connect it to 87.
If you decide to cut, crimp the cut wires (I used 10-12g butt connectors) to the relay harness as indicated in the diagram. Pin 87a goes to the switch end of the IG2 wire, and pin 30 to the other end. Pin 87 goes to the starter thru the firewall, and the switch end goes nowhere - just cover it with electrical tape.
Connect pin 85 to the BRB with a female quick-disconnect, and ground the other pin on the BRB, also with a female quick-disconnect. For ground, use either the original lighter black wire or one of the several threaded studs scattered around the footwell. Pin 86 is connected to power. I suggest the "key-in" line, which is already on the 10amp "Room" fuse. Using the Blue/Yellow line makes sure the relay can't activate without the key in. Or, with some more imagination, you can go through a hidden or disguised switch to provide a starter lockout.
If you need an accessory connector, the blank area on the pax side is a good place in M1's. Just tap a new socket into the existing lighter wiring.
If all went well, reconnect the battery, and turn the key to the ignition position (second detent). Hit the hidden switch if you did that option, and depress the clutch & BRB. Should start right up. If not, check the wiring. If there's a fire, I never heard of you, and this page does not exist.
The above describes the way I did it in nike; in nameless, I used an S2000 button & backed the connectors out of the backshell.