It will just get better. IMO the factory head unit and system sounds like crap. Just make sure that you pick out pieces that will go good together. In other words the Blose speakers may not match well with your new headunit, but they are worth replacing anyways. In a perfect world, new front speakers, new head unit, some deadening, a sub, and a good 4 channel amp is a great first budget system and a HUGE improvement over stock.