Options to replace rearmost little speakers??

[5abivt]

Ok so I want to run subs in the sail panel like stock and got sone own replacements. Some recommended running the rear 4" wires to the sail and run a coax but i wanted to know if there is another option for the little 4" speaker in the rear? The panel that holds it looks big enough for a bigger and better replacement ?

[JaycenK]

A very shallow 6x9. I have seen that done but it is pointless because you have subs so never understood that other than the 3 way part but still. a shallow 5 1/2 can be used with modification but a good mid and high 4 is the easiest and still makes good sound on stock amp.