So i have 2 boxed 12s in my trunk of my 98 escort zx2. The floor of the trunk of my zx2 is about a quarter inch of plywood and a layer of carpet on top of it which shields my tire. I feel like this really detracts from the amount of bass i get from the sub; So today i put a piece of cardboard under the carpet part. Is this a good idea? What would be some other cheap alternatives to get the most bass?