Rear Speaker HELP PLEASE!!!!! Options

[stud97023]

Hey everyone, well im workin on installin my new system. Anyways, today i pulled out the back side pannels and saw the nasty stock speakers. THey are on a really weird looking grey plastic piece (im sure you all know what im talking about). Well i know that i need that plastic piece but i was thinking about putting in 6.5s back there. HOw would i do this? What have you guys done? Also, i noticed there is a lot of spare room in there, so would it be possible to put a 6x9 in there? has anyon done this? Thanks for helping me out, and pics always help!