This part is a lot better than I dared to hope

In my VW RNS 300 a (new version) is installed, no Bluetooth. VW wants at least 600 for a Bluetooth-enabled Radio + installation, since I wanted to first look at the alternatives. This is a very good. Commissioning is foolproof and lasts just as long as you die for the Bluetooth pairing (without PIN) + tuning.
The sound quality is as good radio reception, no noise, but occasionally a slight hum - only audible when engine. By the time you go, you notice no difference to CD quality. Of course you have to remember that the quality may vary with other radios / antennas.
A2DP is fully supported without any problems, so also play next / previous song.
The one star I subtract only because of the imperfect quality. This part provides for cheaper goods from China (does nothing to the functionality). Actually, the "transmitter module" like a magnet connector designed so simply peel and easy dranhalten. The removal goes smoothly, but it is not done with dranhalten. It does not fit perfectly, so you have to push in it / latch. This issue is - as in such quality standard - certainly less pronounced from one device to another. I'll leave it anyway always stuck, I do not care, so it is from my side actually good 4.5 stars.