I haven't seen anyone talk about different speakers and what sizes you can replace the factory ones with. If anyone is putting new speakers in their 03-06 Accent, then definitely go with 6.5 inch in the fronts and rears. They come with 5.25 inch speakers from the factory, but I found out that most 6.5s will fit in the factory spaces with little or no modification. Once I replaced my speakers with 6.5s, my ride has become much more enjoyable and it really rocks my face off!!!!!