thanks guys. im still not quite satisfied with what i have to do. i considered buying a sub and tryign to build a box that fits under the rear deck, but after thinking hard about it, i have decided to stay with a free air sub. i searched google and found some nakamichi subs, 1 10 and 1 12. has anyone ever tried to mount a 12 in free-air sub under the preexisting 10in hole. if you have, what tips would you have for this type of mount. also, how many watts/ohms does the factor nakamichi amp put out?