Re: can i have the bose stereo fitted?
I had a Blaupunkt MP72 in my 155V6. It had a funky little microphone which adjusted the sound equaliser to the cars interior. It also did a whole range of other stuff like volume adjustment based on speed.
Aftermarket headunits are massively more sophisticated and capable than the units in cars as standard. My 155 had a set of quality speakers front and rear, can't remember the brand, but they were very good, and the Blaupunkt headunit. It sounded brilliant.
The Alpine setup in my 156 cannot touch it at all!
Go to a good ICE shop and talk to them about your needs, it will be cheaper, less involved and almost certainly better sounding than trying to retrofit the BOSE system which has its own wiring harness and bespoke parts.