The inexpensive car ionizers (ozone generators) that plug into the 12v cigarette lighter outlet are, in my experience, pretty lame. Car detailers use bigger units with great sucess. If you are handy with a soldering gun, you can easily build one on the cheap from parts available on eBay. I wonder if you could rent a commercial unit somewhere? They are pretty fantastic, just don't run it while you are in the car. Ozone is bad stuff for mucous membranes. Lungs don't fare well.