adding sub to factory system

have a 2000 mitsu diamante (japanese right hand drive version) which is equivalent to a 2002 american model.. it has an infinity system with navi controlled via touch screen and there is a hole in the rear deck that looks like it cud hold a 10" sub.. anyone kno if this system uses an external amp and if so, where is it and can a sub be run off of it??

You have an infinity amp under the seat, but it will not run a aftermarket sub.  You can run a lineout converter from the infinity amp to signal an aftermarket amp.  Keep in mind that your sub will have to be a free air sub if you are going to use the existing opening.Do it right the first time

thats where i thought the amp was but when i had asked the owner of the car he told me he didnt see anything under there.. is there another location it could be or is he just blind???.. considering using factory location for sub but building a fg pod under it.... btw.. do you know if there is a way to change the japanese writing on the touch panel by reprograming something or is he stuck guessing what it says??