For the first solution, user will think if there’s more function like: I want to see my car on the map. I f there’s several cars, what shall I do? Can I store all the coordinates for a trace?

The solution II & III has more exciting functions let user to make it. User need connect a GSM modem with computer, and then install the software to pc. The software runs into mode: GSM or GPRS. If there’s no internet connection, you could use GSM mode; if yes, user could track real-time and see his car on the map.

The difference between solution II & III is the working mode:
Solution II: SMS,
This solution can show the location on the map. it could work without internet connection. And user could control the cost for tracking which only come from SMS charge. But the speed to send SMS is slow. It’s can not track real time and has no functions as GPRS.
Solution III: GPRS.
This solution can show user’s car real time on the map. And it use GPRS to transfer information, it has more powerful function as the mileage, history trace and so on.

Both of them have the vehicles information management function. Because it is designed for one computer, so the suggestion MAX 50 vehicles.