I actually like it even better now. Thats a really cool idea. In case you havent tried it (i'm sure you probably have) it works. I read with my droid and pulled everything right up.
We drive huge 16 passenger vans where I work and they actually get pretty good gas mileage. The inside of the van could be customized to your preference.
Or make that an optional (premium) badge. Those badges would run into some money printing them out for a bunch of people. They charge $7.00 a piece to the residents at my work. It might not be worth it if you had to buy the equipment just to use once a year.
Unless it is a surefire or that type light you wont get the intesity out of it like a dedicated swirl finder. Most that I have seen have dual bulbs. I would actually like to see if a led light would pick the swirls up. I wouldnt see why it wouldnt you just need to make sure you are putting out a...