Servus people ! 🙂 Have the original radio in my convertible and the Bose sound system. Does everything work but I want to install a radio with CD box and USB port. Before I buy twice, what do I have to bear in mind ? China trash does not come in to me, should already be a brand manufacturer. I have to pay attention to what because I have the Bosezeugs in it or ? Are there good adapters, the Radio 4 preamp outputs must have or what is to be considered ? Have no plan of radios. :-/ Thanks in advance 🙂