Do any of you use any vehicles with CNG? Sounds great for taxes- state and federal tax credits, and you get $.50 per mile even if actual cost is only $.08 per mile. In my state you can use the HOV lane solo, plus other incentives. I'll be the last one on earth signing on to the "man made" global warming, so I'm not as concerned about that, but low operation cost and other benefits sell me. If you use them, did you buy them or convert them? You can get a home fuel compressor, too- that makes it even cheaper and more available. What are your thoughts?