Okay, so I was reading
THIS article. It seems like what we would need to do is get an RFID setup to trigger a
Omege IM04 Bypass Module, which would in turn bypass the PATS. Apparently that's the bypass a lot of installers use when they put remote starters in cars with PATS systems, which normally just shut the system down until the car is started, but can be adapted to keep it off as long as the signal is detected. RFID shouldn't be too hard to do, my firehouse has an RFID system to get in, the only problem is that the little fob needs to be put within an inch of the transceiver. Some other firefighters that I'm friends with, their stations' systems will pick up the fob in your pocket from a few feet away.
Now, having experience with friends' remote starters, you still need to put the key in the ignition, or else the car will shut off once you depress the brake or try to switch gears. I'm not sure if this is a feature of the remote starter system itself, or a byproduct of the PATS system. If it's the starter, we're good.
The trick would be to get an RFID system that is good to about 5 feet, that way someone can't steal your car if you're 20 feet away in a convenience store or something.
The only other thing that I can think of that needs to be dealt with is the steering wheel lock, but like someone mentioned, that isn't too hard to take out.
As far as ACCESSORY, I'm still a little confused about that. When the key is turned to RUN, it activates every electrical system in your car, ACCESSORY just turns on the radio, etc so you can listen to music or whatever without running your fuel pump and everything, right? So, as long as you wire it right, the RUN switch will still work as usual. The only problem is when all you want to do is listen to your radio. I, for one, have no problem with three switches, 2 On-Off for accessory and run, and 1 Momentary for start. That way, to start your car, you just flip the RUN switch, and then hold the START switch/button until your car turns over. It's a whole lot easier than the microcontroller that inh was referring to. However, if someone were to want just one switch to do everything (like my friend's Nissan), then you'd have to get into the more advanced stuff.
So, if I've got this right, this is how the sequence
should work (for simplicity's sake, I'm not including the automatic unlocking that some people mentioned).
1. Get in the car and sit down on the seat.
2. RFID system recognizes signal from key fob in pocket.
3. RFID system activates PATS bypass.
4. Bypass shuts down PATS system.
5. Turn RUN switch to ON, thereby powering all of the car's electrical systems.
6. Hold down START switch/button until engine turns over.
7. Shift car into gear and drive off.
8. Drive to wherever you please.
9. Stop, put car in park (parking/emergency brake if required, obviously).
10. Flip RUN switch to off, thereby turning off the car, just like turning the key off and taking it out.
11. Get out of car, and once you're however far away, RFID system loses signal from key fob and turns off PATS bypass.
12. PATS system is activated, thereby leaving your car as safe as the original system. Even if your car is broken into and the switches are played with, car won't turn over.
How does that sound? If that works, all we really need to do is find a compatible RFID system and get the wiring all figured out.