I read about this tip in a magazine and thought I would pass it along. The next time you buy a product and it is packed with flat styrofoam do not throw it away. Cut the sheets so it will fit under the lids of your cooler and live-well. It will be best if the sheet is about the thickness of a styrofoam cooler that you would buy.
The house I bought had part of the basement finished in 12"X 12" styrofoam squares. There was several sheets left over so I put them to use. If I had to guess I would say they were 1/4 or 3/8" thick. 12" was not long enough so I had to use 2 in order to get them long enough. I also double stacked them for extra thickness/extra insulation and then I cut them to the right length. Then I wrapped duct tape around them to hold them together. I used double sided sticky tape to attach it to the bottom side of my lids.
My lids already had insulation on them from the factory and it done a nice job of insulating my lids. I have owned my boat for 14 years so I know how well it holds ice in the summer. I added the extra insulation about 2-3 years ago and I have noticed that my cooler holds ice better now. I have never paid attention to the live-well temperature but I am sure it helps hold the heat away. If this is something you decide to do it will cost little to nothing and improve the function of your cooler and live-well...saw this forum and thought I would share.