I have this system in my car. PM me if you want one.
I have a pretty simple setup in my car. Cheap rfid reader from ebay wired into the central locking.
Reading distance is through metal/glass so the card/fob has to be within 10cm for it to unlock/lock but that is all I really need.
do you care to share any details?
i have really started thinking about this, and the obstacle i am running into is getting both lock and unlock functions from the modules.
i can easily get the module to lock, or unlock the car by presenting a different key, but am unsure how i could do it with a single key--i'm thinking of using a present2 or present3 rule to unlock the car, but i don't see any rfid stuff that works that way..(most of the expensive stuff i've worked with before uses a present3 rule to keep power applied to the door mechanism to keep it unlocked until another present3 event is actuated..)
looking at this redbee reader right now(link)-- that has the amount of outputs i need, and plenty of cards, and can operate in standalone, i just need to figure out the lock/unlock issue..
Next plan is to hook it up on a timer so that say 20 seconds after ignition is cut, doors automatically lock.
Like this http://www.sparkfun.com/tutorials/135. The benefit of using the nike+ is the fact that it is really cheap, it is highly energy efficient since it is intended for mobile use and you get the quality associated with ape as opposed to no name eBay gear. The problem with passive RFID is the range is at most a foot and when thier is solid metal in the way I'd be suprised if you could even read the RFID chip at all. Th other benefit of Nike+ is it doesn't handle any of the logic relating to unlocking the car. It just passes along any valid Id's it gets to the serial line. This means you can have an arduino handle the alarm buttons and programming new Nike+'s that can unlock the car. Here in a couple months I'm going to be taking on this project but instead of the nike+ unlocking the car im gonna have a capcitive touch switch either in the door handle or on the window that unlocks the car and sets the ignition to on but only if the Nike+ is in range. Then when I get in I'll just have to press a button to start and not worry about where the key is at.