I built one this past year. Took 2 days to make by myself.
--You need at a minimum a radio(DUH). I purchased one with a front input jack for easy iPod connection and a remote so I don't have to get my lazy arse up to change the station or CD track. Runing the CD player runs the battery down a lot faster than the radio or the aux input an iPod would use.
--Car battery. Doesn't have to be deep cycle like some would suggest. A normal 12V car battery will last you more than a day of continuous play time. I got more than 2 out of mine.
--Ice chest (self explainitory). I used one with wheels on one side because all of this equipment is HEAVY.
--Power switch. Get one from Wal mart of Radio Shack for $2. Got to have 1 because when not using the radio, you have to cut power to it or it will drain the battery.
--Jig saw for cutting holes for speakers.
--Some type of sealant to fill the holes around the speakers because you won't cut perfect circles. There's probably going to be gaps. I used simple sticky-sided styrofoam strips I got at Wal Mart. Worked perfectly.
-- Radio atenna. I used one of those black rubber ones (no jokes guys). Important to make sure that the thickness of the top of the cooler is thin enough to mount the attenna. Too thick, and the top piece won't screw into the anchor piece on the underside.
--Speakers. Pick your choice. I went with a couple of 3" and 6.5" rounds. You can use what you like, but the bigger the speakers, the bigger the chest has to be. No need for an amp! Trust me on this. I could out blast half the people around my tailgate even though they had home systems set up. Besides, battery won't last for shite.
ETA: I'll post picks and you can ask me for any advice.
This post was edited on 6/19 at 11:14 am