Here’s a tip for those who want to connect their smartphone to the radio via Bluetooth, but who (like me) have the GROM solution too expensive. Briefly to the background: I had previously installed a Bluetooth adapter from Adapter-Universe in my C30 with high performance audio system, which had a good sound, but often failed (which is, of course, impractical, as it was at the back of the radio unit). Since the GROM solution was too expensive for me, I spent a while with it. In the meantime there is GROM but also a kind of replica called MR12Volt. Works very similar (i.e. music and hands-free function via Bluetooth with display on the radio display, operation via the steering wheel or the operating buttons in the waterfall console, USB port etc.) and can be installed invisibly. I ordered the good piece once fun for almost 140,- at Ebay and up to now it works perfectly. Not even MOST-security had to be turned off (w Of course I can’t say anything about the long-term stability yet. 140 Euro is still a bar of money, but there are many other possibilities not to expand the functions of the audio system. Maybe this helps one or the other here, if it has not been posted somewhere.