Did you leave the Bose woofers connected also and add the JL Audio subs or did you replace the Bose woofers? I have a convertible with the 10-speaker Bose system, which has two 10-inch woofers (1 in each door), two 5.25-inch full range speakers behind the seats, and an 8" sub in a box in the trunk.the stereo upgrade is a must, as the Bose system is really lacking of any presence (sharp mid-bass, and hard hitting bass) the JL 8" tw3 cabinet works very well with the amount of airspace in the stingray. The amplifier is your standard Rockford Fosgate punch 300-1 mono block amplifier, it produces ample power and is very controllable with remote switch. The trick to the installation was finding clean signal out of the Bose components. We ended up taking high level input signal from door woofers, as every other source was polluted with signal noise that made the subwoofer "fart" whenever you pushed the accelerator. The door woofer signal was the only clean signal in the system.
The hush mat, Sound Dampening, Vibration Damping, Thermal Insulation for automotive applications - HUSHMAT. will be added on the interior surfaces of the fender wells, and perhaps the floorboard of the vehicle in an attempt to drastically reduce road noise. ( what's a few pounds of stuff, compared to unbearable road noise)? I've used Dynamat, hush mat, in other vehicles, and it does a tremendous job of reducing unwanted noise.