The RTLS solution USES a matrix of sensors, one for each zone, to receive radio signals emitted from an active RFID tag affixed to the automobile's frame.

It took less than 10k of JSP code to implement a set of tag files that produce the basic form elements: lists, text fields, radio buttons, check boxes, and submit buttons.

A far simpler kind of chip called a radio-frequency identification (RFID) tag, which sends a tiny quantity of data over a short range when activated, can already be manufactured for 4 cents apiece.