Hey, I got a racquetball sized ding in my rear quater panel. No paint cracks or chips, just a good ol fashioned dent. was gonna try a heat gun and a rubber mallet from inside the trunk trick and pray for luck, but then I found this...anyone ever tried these methods? Text (w/vids) from: http://www.diylife.com/2007/08/01/how-to-freeze-dents-off-your-vehicle/
Solid carbon dioxide (dry ice) - I'm sure you've come across dry ice at some point in your life. It's readily available (your local grocery store probably carries it) and is great for freezing all kinds of stuff, from ice cream to warts. To remove a dent from your car with dry ice, simply apply a chunk to the center of the dent, and hold it there for up to a minute. Every so often, lift the dry ice to check on the dent. It may take several tries, but the dent should eventually pop out. Once that happens, allow the area to warm up, and then clean it off with a terry cloth.
Liquid carbon dioxide - If you're not too crazy about the idea of handling dry ice, liquid carbon dioxide might be a little more user-friendly. If you have a fairly fresh can of compressed air, you have more than enough liquid CO2 to complete this project. To release it, simply turn the can upside down and aim it at the dent. Before you do that, however, warm up the dent with a hair dryer for roughly a minute. This will help the sheet metal relax and expand, but then, just before the dent starts to doze off into a peaceful slumber, you'll jump in with your can of liquid carbon dioxide and freeze it to death. Spray the entire dent, then step back and watch the magic unfold
