Check this shield out, it sounds exactly like what you need, plus it has OBDII (CAN) access to log RPM, indicated speed, steering wheel angle, and whatever else your car exposes. You can get a GPS module from Sparkfun as well. Matter of fact, I'm using it in a very similar project, but development is paused until I upgrade to a Mega, since I've run out of RAM.
The shield comes with example code that's hacked together from other sources but it serves the demo purpose well.