Just a general question and a thought here. The Pixhawk with GPS seems to have all the things a basic (or not so basic) car or bike racing track logger might need.
Using the accelerometers and GPS position it could record cornering G's and speeds, and do lap times based on crossing the same virtual line, a bit like Copter or Plane crossing a waypoints radius.
Home Position could be set to the start/finish line perhaps via Mission Planner.
A few extra sensors for temperature or rpm could be added via the analogue in or I2C ports, maybe even OBDII via the CAN port.
Is this a unique idea or has some code been created already by to use Pixhawks hardware in this sort of way perhaps ?