Auto ready Push Button Ignition? suggestions?

[Nerys]

On some new cars they have a neat feature. the KEY has a long range RFID type of thing in it.

when you get into the car simply BEING IN the car with the key is enough to act like you turning the key to the ON position.

all you need to do is press a "start" button and the car is running.

HOW would I go about doing this (yet still having the original key work as well)

ie I want to get in the car and press start WITHOUT having to put the key in or turn on or do anything else.

I can think of a few steps. Find the 2 wires that put the car into "on" position and wire them to a relay. have the wireless thingamabob turn on this relay.

find the wires that run the "starter" from the key and wire them to a BUTTON

that part "seems" easy enough

how do I do the wireless part?