TeDy

All though you have a valid point, and a good one, but the Z2 was designed for navigation too. If the navigation doesn't really work, then thats like paying for a $2000 Ipod/cd/dvd head unit (which there are several out there for a lot less then $2000)

My guess, if there was a replacement screen, it would more trouble then its worth. But, the chances of a replacement screen are probably slim to none.

Don't quote me since I'm not too sure about this, but maybe your VSS wire?

Blown speakers are cause from too much distortion. I wouldn't recommend just changing out your speakers every time they blow. Thats like doing the same thing over and over and expecting different results. As for the whole different sound, it's either the amp can't produce that much power or something is wrong with the wiring. Wire up the speakers to the deck and not the amp and see if it still does it. If it does, then something is wrong with your deck. If not, something is either wrong with your wiring to the amp/speakers or there is something wrong with the amp or your amp settings are s