ignition switch wiring?

Hi,  I'd really like to make an ignition switch using one of your relay diagrams where i put a momentary button in order to start the car my question is for an ignition switch, is it necessary to use a relay since I'm only trying to start the car once so then i could just use a momentary button, if a relay is required then definitely I will use your diagram and wire one in.  Other than that, I have an Integra 01 and i'm clueless as to how to locate the ignition wires in order to splice in the correct relay/switch.  Thanks for all your help!

not on that car, it has an immobilizer which means you would have to bypass that, if you are trying to do an s2000 style start button I would try www.team-integra.net . its really not that hard to do, you put the key in, turn it to on, which disables the immobilizer, push a button which throws a relay hooked to 12 v and sends it down the starter wire, just like a remote start....