Josua and Rexter314, thanks for the tips, and following original harness for wires is always a good idea, I will make sure they take no shortcuts. So after telling the custom stereo shop I am working with that I do not want amp/radio in the trunk--this is what they said are doing now. Since the Bose system is actually running at 250watts and the new units are like 50watts, they are replacing the original OEM amp with a new one integrated with my new double-DIN Sony to drive all the speakers in the Bose system adequately (even the ones under both seats which I didn't even know were there!), doing that, I can get rid of original radio/and amp like you both suggested was possible. USB connections will be in center counsel. They claim it will sound a lot better than original--albeit I am usually just listening to the Corsa exhaust! Back up camera of course going in--main reason I am doing this truth be told, and they are making a custom bezel for the mounting, etc., I will post pictures and details of what was used etc. when it is done and put my car photos in the garage which I have not done yet. Cheers.