I am looking at getting a Pioneer D3 nav unit in my 01 mustang. What I am wondering is if it is worth it to put new speakers and amps in at the same time. Would I notice much of a difference in how the system sounds if I put in some decent speakers? I wouldnt want to spend more then about $200 total on speakers. I should already have the amps I would need because a friend sold me his old ones for pretty cheap. I currently have the Mach 460 with a 10" Diamond sub in the trunk.