The aftermarket is the best option in this case, as the Optitron (Multi-information Display) that is standard on all other grades, will probably cost you over $1,300! As for the free iPhone apps, none of which connect into the cars electronics like the suggestion above, I have tried using these in the car (and rating, asterisks out of 5): **** Rev Lite (Accelerometer and other telemetry with hardware connection) - I could only use the accelerometer (don't have the hardware) but its the best I've used! Peak g's can be affected by engine vibration, but thats no fault of the software. Looking at the potential, I could see giving it 5-stars if I had the hardware to connect to the vehicle! ***+1/2 TrackThing Lite (uses A-GPS to work out an map/graph speed (current/average) , distance, altitude and location) - for highway use only, gives accurate average speed using A-GPS, but live speed fluctuates. Uses Google maps to plot position and heading. ** PocketDyno (you drag and it collects data from accelerometer) - proved difficult to use safely on the road and didn't give consistent results *+1/2 Speed (shows speed only) - limited by A-GPS. * Max g Force (shows current and peak g's in one axis) - not useful in the car. MotionX GPS LTE - Just started testing, so no feedback to date. Looks to have some potential, but equally difficult interface. I'm interested now in some OBD-II hardware ... but as I can bring the Intelligent Tester II home from work, maybe it's not such an advantage?