I bought a fridge fin fan for our RM2852, off ebay and finally "Installed" it today. Since a pic is worth a thousand words, here's the pic from the listing:
Clicking on the pic, will take you to the ebay listing...
The "Installation" consisted of routing the positive wire to the light and putting the wire inside the positive spade connector, for the light. To both ground the unit AND mount it, there's a green alligator clip at the back. The alligator clip grabs one of the fins and there's your ground, as well as the mounting point.
It'll do, until we get back to civilization. I'll re-engineer the mounting system. I do like the concept though... NO batteries!