Mach 460 Speakers for 04 Mustang Convertible

[marly]

I currently have a 2004 Mustang Convertible with the Mach 460 Audio System. I'm replacing the HU with an Eclipse CD8455. I'm also planning on putting in Memphis MC57's in the front. I was thinking of putting MC57's in the back, however, I'm not sure if those will fit in the back for the convertible. Does anyone know if MC57's will fit in the back on a 04' convertible?

Also when putting in the MC57's in the front, do I still use the tweeters that are up by the Windows in the front or does the MC57's replace the tweeters as well?

In the future I plan on putting in a sub and replacing the Mach 460 amps as well. If I replace the Mach 460 amps do I need to run any new wires or anything or can I use the existing wire?

Another thing that I have a question on is, does anyone make wire harness for replacing the speakers? I would hate to cut the wires and wire them directly if I want to replace the speakers back to the factory speakers if I ever sell the car.

When replacing the factory speakers with the Memphis MC57’s does anyone think I will notice any difference in sound quality from the factory speakers? The MC57’s seem like half way decent speakers, however, the price on them is fairly cheap ($100) so I’m wondering if it’s even worth spending the $$ on replacing the speakers.

Thanks,
marly