after an impulse buy of two boston acoustics speakers on ebay, and a christmas gift stereo head unit (it's one of those ones that automatically hides the face. i spent at least ten minutes just turning the car on and off just to see it work. i'm easily amused.), i finally realize how HORRIBLE the existing volvo and radio shack-rigged sound system was. SO now I'm thinking about doing some sound proofing and adding some rear speakers. I just wanted to know if there's a pre-cut hole or something where I can mount speakers in the back, and if not, where have any of you put them? (i drive a wagon, just to clarify)

Thanks