[03stang]

I'm trying to find the data cable to tap into for a line out converter, to add a sub to my car. I used to have a 96 hardtop, and the amps were right under the rear speakers, but i just got a 03 convertible. With the speakers on the side panels, i'm not sure where the amps/data cable is. Is it under the speakers, behind the seat? Any help would be appreciated. Thanks.