crutchfield.com allows you to build a sound system with only items that will work in your car. im sure best buy has something like that. also since you are in there replaceing speakers get some dynamat to give you extra insulation. or tell the people that will be installing the system that you want dynamat. its a little pricey, but it will make everything sound so much better. as far as speakers go im a fan of Alpine, all the cars that ive put upgraded sound in have always used Alpine. I have not done anything to the sound in my crossfire, i like the sound the way it is, but several people have and there are threads on this forum about removing the door panel and rear speaker covers. remember our cars have side airbags and they can be touchy.