Is it possible; Xbee, Zigbee as "proximity sensor" for keyless entry keyfob?

I am converting my car to a push start setup using an Arduino and would like to create a proximity keyless entry system. The only device that came to mind is Xbee-Zigbee. Can anyone help, or is there a better solution?


The XBees don’t have any built in proximity functions. If you want to use them to transmit the “unlock” signal or something, they would work, but there’s probably something out there that’s better for measuring the actual proximity.