Thanks Dirk, great advice, agreed and I may go down that path…. although before I do, I am exploring all options before installing a third party unit.
I was also going to upgrade the Becker radio and then found with modern technology you can pair a quality portable Bluetooth speaker to your phone and voila, amazing unlimited music with no additional changes to the originality of the car.
Sooooo I was hoping their may be an aftermarket portable unit that does the job without changing the cars structure. I await further responses. Failing this, I proceed as you described.