It all depends how hot your amp get when there int he open.. you could always cut out a little more then lay some fiberglass inside of it then put a fan to remove the hot air then lay the stock carpet back over it.
Or not do anything just put the amps in. It all depends on air circulation and exposed heat sink area. you could always get a amp like the Kenwood Excelons that had built in fans on the top and do it.
