I've been dealing with this issue almost since I got the car, which was April 1st 2014. It's an intermittent issue that I can't reproduce but I have provided plenty of evidence of it happening. When listening to Bluetooth, randomly, the sound will completely cut out and I will head nothing but a high pitched tone. Turning off my phone doesn't fix it, switching to another input and the back doesn't fix it. I should say that if I switch to FM for example, the sound does work. I have provided videos of the problem, which happens every 2 weeks, give or take and seemingly has gotten worse.
The dealer replaced the stereo 3 or 4 times and the MDI unit once, each time, same problem. They told me the problem was my phone not being compatible with the car, a Google Nexus 5, I need a new phone anyway so I bought a one plus two and happened again! This time Crosby and VW told me that I needed to use a mainstream phone as somehow, the Nexus 5, made by LG isn't mainstream enough. Okay, I ended up borrowing an iphone4 from a friend and probably a week later, the same problem happened again!!
The dealer had told me that the same tone issue happens in Passats due to corrosion issues with the MDI device, how in the world does this happen due to a manufacturers defect in Passats but on my Jetta, it's related to my device? At this point the deal basically told me there is nothing else they can do and closed the issue. I now have to deal with customer relations and they are pretty unresponsive.
On top of this, when I first bought the car there was the block heater recall. A voluntary ECM recall, the diesel recall, which is ongoing. And I had another fun problem where one day, I get in the car and the passenger window is down. Try to roll it up and it goes right back down! I called the dealership, they didn't return my call, drove to the dealership, they took the car and 'reset the software' which fixed the problem but they couldn't give me a reason as to why it happened.