if u r talking about the ones in the front doors, you can get 13cms in there, if u r talking about the ones in the front dashboard, i wouldnt bother, id disconnect them, cut a hole in ur door card and use the pre cut 13cm hole in ur doors and cover thew door card hole with new speaker grill!!!!!!!
obviously make sure u take door card off first and cut hole to fit hole in door and make sure it is smaller hole than the speaker grill!!!! hehe