I installed the AVIC-Z1 in my 2007 Jeep Wrangler Unlimited X with the help of a professional installer.
We took the old radio out, performing surgery on the Jeep to fit the AVIC-Z1, the whole was to small. He hard wired the speakers, power and took the ignition from the cig. lighter. The VSS we picked up next to the computer in the engine compartment. The GPS antenna I left on to of the radio, covert by a plastic cover.
All works great including the by-pass.
The only problem is the iPod, all the controls work, but no sound.