Larry,

If I understand the model and setup you are referring to, those Supras have a complete wall that the woofer is mounted to. The 2nd issue with the moomba, is that the wall is open at the top. In addition to a true free-air woofer, you need to have 100% isolation between the front of the woofer and rear of the woofer. It is not practical to do this on a moomba with the helm wall like pictured above.