You could try an idea that I have been toying with for my jeep... Mounting one or both of my amps under the hood.

An even better idea would be to take your amplifier, fill the bath tub with hot water, power the amp up, then drop it in. After you've finished with that, put the amp on the sidewalk, and beat on it with a hammer.

The end results would be comparable to your scheme, and would have the advantage of being easier, saving time, and requiring fewer resources -- I mean, everybody has a hammer, right? In a pinch, a large rock would serve...

tanstaafl.