The reason I switched mine out, I had just redone the stereo, head unit, all 4 door speakers. It was sounding great, then it would start cutting out randomly.
Finally tracked it to those roof speakers. The wire had come off the cone, and was contacting that metal plate they're mounted to, which shorted out my whole system.
BTW, does anyone know if there's a place you can buy those grilles that fit up there? I've taken mine down so many times, they're all cracked. The fabric still looks decent, but since the plastic grille is broken, it kind of sags down in the middle.