Interesting idea, but I would think that rain, snow, etc would get in there and ruin your electronics. If you really did want to do it though - all you would have to do is cut a hole in the trunk to match the one in the quarter panel. Then run some type of tubing between the two so that the air flows on to the amps. I would not recommend this though. Your first drive in the rain could prove to be fatal to your system! Why not just run your subs at an OHM that your amp is stable at - then you won't need external cooling.