I have the Auto Engenuity, does a good job. I did not purchasse the extra Mazda enhanced interfaces. It is not good for realtime readings while driving though, unless you want to take your eyes off the road to look at your laptop. The Speed Racer that came with it will let you read boost, dyno, acceleration, deceleration etc, but after the fact unless you have someone riding with you. I would call it a good "after the fact" diagnostic program, or for tuning on a dyno, but not while driving.