Upgrade from a standard stereo system to Mcinstosh.

[K_Senhor]

Hi. So after a few hours searching, and after place my presentation, I still not finding useful info about what I need to change my stock audio system to the optional Mcintosh system. I've OEM Nav and the stock audio system which is from Kenwood I think.

What really is needed?

Can I install the main unit with the A/C and the Amplifier with the original speakers, and later install the Mcintosh speakers when I get it?
Do I need to get any cable for this, or are they hidden?

Thanks