Well not quite, but nearly. A while back I reviewed the ScanGauge II in-car computer. It hooks up to the OBD-II port on any post-1996 car and gives you all manner of readouts that your car might not otherwise be able to display. (See the Scangauge II review for more info.)
It's taken a while but I finally caved and bought one of these for myself. The original unit was given away in a competition, but I always regretted that. That being said, I make a point of never keeping any of the demo units I get for review. So a couple of weeks ago I parted with my own cold hard cash and bought my own ScanGauge II. It's been doing hard duty in my Honda Element ever since. I'm really glad I bought it. I've got mine reading out water temperature, instantaneous BHP, average MPG and instantaneous MPG. The MPG readouts are particularly interesting. In the same way that Prius owners unwittingly enter into competitions with themselves to get better gas mileage, I've done the same with the Element. The difference is, of course, the info is available to me now where it wasn't before. I'm proud to say I've added 1mpg to my average because of the ScanGauge II readout. Doesn't sound like much but in my boxy Element, that's a 5% improvement.
If you're a car nerd, or just like geeky, techy things, pop over to the review and decide for yourself if it's worth buying one. I would. And did.