I'm running an ARB 50qt in the back of my 5th gen. Probably the single best mod I've done. Once you go fridge, you never go back (nothing rhymed with fridge). My wife thought it was a little pricey at first...now she likes having it more than I do. She said she can't imagine life without one. I wish she saw all mods in the same light...
I ran 10 gauge wire directly from the battery to the back. Replaced the factory 12v plug with an after market (it's always hot). It's been running off my stock Panasonic battery since August. I can get about 16 hours before the fridge stops running to avoid drawing the battery too low. I will upgrade to the Diehard Platinum 31m as soon as they go back on sale for $217-$234.