Just make your own, Get a heat blanket and cut it up and reconnect the ends. Then take out the seat and the bottom layer of springs and pull out the sponge and place the blanket there. Lay the wire and make a 12v converter and hide it.
<span style='font-family:Geneva'><span style='font-size:14pt;line-height:100%'><span style='color:red'>Fox</span></span> <span style='color:gray'>the Pirate</span>
Diplomacy is saying "nice doggy" until you find a rock.</span>
I live my life one quarter mile at a time, and for those 23 or more seconds I'm free.