Do you send direction to install the unit into my Rexton?? is it plug and play, or must I cut into the existing wires??Do the buttons on the steering wheel control the unit?Do you send the Australia map with the unit? What is the cost for the reversing camera?Do I need to purchase any other parts so the unit will work in all modes, inc the TVIf the unit does not work, will you offer replacement?I look forward to hearing from you.