Hi 04Cali330CiZHP, as far as i can see your problem seems to be something else, at my car the sound stops not the radio it self.
An update for my issue.
I went to a store yesterday that is specialized in BMW parts.
I've called him and explained my problem, immediately he told me the problem has to be the radio module.
My radio module has been replaced, but replaced from an other BMW, not refurbished or even checked.
So far i am driving 1,5 day with the new refurbished radio module, sound works perfect and haven't got the problem.. so far.