I spent about $25. on some double layer foil and padded heatshield insulation material at an auto parts store (Is this the same stuff West Marine sells for $80?!?). Anyway, I just measured approximate sized and then shoved the stuff up through the vent hatch at the bottom of the fridge. You'll have to bear with me and get oriented for this next picture.

I just shoved the camera into the hatch hole and pointed it UP. What you may or may not be able to see here (you are looking up at the back of the fridge) is the single piece of insulation I worked up onto the top of the fridge, foil side up (you can just make out 1 inch or so of the grey backing hanging off the top edge, below the oval vents).

On the left is another piece which was too wide, so I just folded it back around on itself, towards the fridge. I put a matching piece on the other side. What is not shown is the foil tape I then used to tape everything down to stay in place. I didn't try to create a seal around it or anything, I am just counting on the reflective properties to help out some - the insulated padding is not thick enough to do anything anyway.

Well, I had just enough of the insulation stuff left to do the A/C compartment! I am not sure if it will do anything, but maybe it will reduce the sound a little (it isn't that bad anyway). Or maybe help the efficiency just a tiny bit. I had to do something with the stuff anyway!