Dr. Mankiw is kind enough to post this which makes me wonder what our future brings.
I may regret writing this. AK and were talking at work and he mentioned the ability of taxing authorities to access the computer in your car. I contains any number of different datum. Add to that, many vehicles have a tire pressure monitor. So here's the scenario: you go in for your emissions test. The technician connects in to your vehicle's computer which indicates you have been driving with a tire pressure less than that recommended for your vehicle. In addition to the results of your inspections, he hands you a bill for an "excess carbon emission regulatory fee" because your underinflated tires resulted in a lower efficiency.
Good thing nobody reads this blog, huh?