I have a MS75, which I took deliver of on March 18, 2017. Today I had my first real glitch. I was driving and I heard what sounded like a pulsating repetitive noise from the front. I don't have a front motor so I was not sure why I had a noise. After trying to change audio stations, mute audio, turn on wipers and windshield washers (things that could be in the front of the car), I pulled off the freeway. Even when the car was off, and I exited, the "bump -d- bump -d- bump sound continued. I pulled out the USB drive. No change. I selected a song through my iPhone. Sound continued. I changed streaming channels. Slow to change channels but sound continued. Since I thought I'd be late to an appointment, I went to call my appointment, and once I dialed the phone through bluetooth, the sound stopped. Started again the second I hung up the phone. I was puzzled, but did a reset of the center screen and the noise went away. Any ideas?