[kaigoss69]

That's the thing...to overcome the sound dampening properties of the closed trunk, you have to throw enormous amounts of power behind it. Then, and only then, a fraction of the sound energy makes it through to the cabin. The majority of the sound energy is used to excite (rattle) trunk panels. In the convertible you have to use even more power, since you don't have a traditional cabin, and there is less cabin gain. This is like shooting cannon balls at mosquitoes...