Car Tracker by SMS & GPS

This software works like a master and slave.
Master sent SMS with password to slave device for location of slave device. Which slave device is cell phone to be placed in car.
This software to be installed in slave device checks incoming SMS. If password is correct, find location. Without disturbing the slave device. If the password does not match. Slave device work as normal. In case SMS match with specified password.
Software will turn on GPS to determine location and turn off GPS.
If signal from satellite is very weak. Find the location from WiFi.
If do not have WiFi signal. Find location from cell phone tower.
Then slave device sends SMS message in form http://maps.google.com/maps?q=x, y returned to master. Master click this link to get the location of slave device or car.
Master device does not need to install this software. This software should be installed on the slave device only. This software can be available on the old android since version 2.3 and above. Can be applied with baggage etc.