Gas mileage
My Audi now has about 5600 miles on it and I've noticed that the average gas mileage has increased from 18.8 mpg to 20.3.mpg. I'm not sure if the improvement is due to engine break in or my driving technique (or both). I set my trip computer to always display my instantaneous gas mileage--I believe Prius's also do the same. I definitely find myself monitoring my gas mileage and how my driving style impacts it. Around 10 years ago, I remember one of the Big 3 auto manufacturers sold a car that displayed speed in a Heads Up Display (HUD) like a fighter plane. Seems like bringing back that technology for MPG rather than MPG would be a useful feature.