youd want to soundproof that thing like mad to keep it from rattling. maybe enlarging those holes a TON would help but that requires lots of cutting metal
also, i was wondering what kind of materials are best (easiest to cut and shape, lightest, etc) for making things like custom false floors and etc..i had one before but i just used simple plywood, plexi and carpet, until i got rid of it when i got a new sub box