That's a great Idea, I did this using piggyback spade connectors. It is only on when the fridge is on. I used a very low wattage computer fan located on the middle rack and made a shroud to prevent covering it with items. I then added an outside cooling fan controlled by manual switch wired through a thermostatic switch mounted behind the fridge access grill. Very low wattage, low noise, and quite effective.
There are pics on Keystone forums under Lunge Motorsport profile pics.
Yes the mighty little BMW 1800TI is leading the Shelby...The Porsche is lapping us both!