I bought one during my vacation for about $2... thought "Maybe it's too much" and then after a month found almost the same stuff in a supermarket for almost $8!
It is hold to the AC output, in my Path I use the passenger side (of course, I have to ask my wife "Please, give me the drink")... :bow: I used it last weekend when offroading and everything was ok... it is easy to plug and unplug, and has the advantage that if it is a cold day, you just need to keep the AC very cold, and your beer will be cold too...