check out my list too...

the only speakers worth changing to are component speaker sets, and the only ones worth spending money on are 800 upwards. although there are few models around 600-800 that arent bad. look up thread discussing good brands for speakers first.

yeah its at dashboard, not sure 4inch coaxial can fit in or not, if got money buy 4 inch component, anyway let a good shop take a look, just in case need some modification to fit in..