My car currently does not have the concert sound option so I have never seen one apart. Some research indicates that 5 1/4 is the size behind the grille? It looks more like a 4x6 size to me. Anyway, here is my question, what is the factory speaker size for the doors. Do you need to modify your doors behind the door panel if you did not have concert sound from the factory? Do you need to cut sheet metal etc? I am stuck between getting a set of concert sound door panels and adding them or buying the G-body parts panels GBodyParts.com Online I prefer the look of the stock door panels but do not want to cut up the car. Let's face it, 3.5 inch speakers in the dash sound like poop. Thanks!