Holy crap, that is a cool idea !!! Many thanks for the link to that one. I was pretty much sold on that until I saw the Yeti name, and I quickly backed off. And you have to invest some time into making that Yeti cooler work properly. Not everybody has the skills necessary to make it as clean as that guy did.
Knowing how much they charge for a standard cooler WITHOUT the speakers, I think I will go back to my budget build with the Kenwood and MCM 8" pods. That is a hard setup to beat for the money invested.