How about an LED bulb?
http://autolumination.com/Also, I had a 20" blacklight neon in the trunk of the Contour. I hate to cut wires if I don't have to, so I unplugged the plastic housing with the bulb, cut the cigarette lighter adapter off of the neon, and crimped a pair of spade connectors on the end of the wires and plugged it in like stock.
