Take a look at the following link:
h
ttp://www.gpss.co.uk/chase2.htm
This guy has created a free GPS software called GPSS. Along with this he describes vehicle tracking using a GPS receiver and mobile phone. His pages are of poor quality but this is made up by some stunning software.
I would recommend starting at his home page and working from there. I have not worked out yet what exactly he used to make this work but looks promising.