I don't currently have one, don't think I've ever seen one on a car, and don't know if it's worth the time and money?

E-Bay item (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2407731577&category=6769)

They aren't worth anything unless you have a problem with the fuel in your carb getting too hot. I personally don't know of anyone who needs one, but I also don't live in southern Texas. I'm still expecting snow this week. 8-)

Dave