I am new to this car audio stuff and I am a little purplexed in understanding where to place a subwoofer in a car. I have consulted with several car audio shops and they have given me mixed opinions (like having the subs fire forward, backwards, down or up). What is the difference and what kind of sound will I get if the subwoofer and box is firing rearward as opposed to forward (or up or down)? I was considering placing my subs on the rear deck of my car firing up just like the '66 fastback Mustang in the Polk gallery. Is this advisable, and what kind of sound will I get? Some shops have advised me against this way, but I am looking of sound quality, and I do not want the bass locked in the trunk of my car. I want to use a sealed box. Any advice and help from fellow Polk enthusiasts would be greatly appreciated.