okay so i just bought this car. i did have a 1988 mercury cougar with the same subs in it, they used ta HIT HARD! in that car. now in the mercedes they hit just as hard. in the trunk. but you can barely hear the BUMP inside the car. The back seats do not go down.but inside the trunk on the back side of the back seat, theres this big metal shield that i dont think should be taken out. could that be my problem?. if so, how do i get around this. put just one 12' sub in the back seat, and tint the windows? does anyone know what the metal shield is? it connects into this pipe and i think goes around the trunk on the side of the gas tank. dont think its connected to the gas tank. but it could be.