Scott, Definitely take it back to the dealers. At a month old, my '14 HSE Meridian system had a vibration/rattle from the drivers speaker. Hadn't even got the volume to half way at this stage. Dealer mentioned it was more than likely loose speaker mount screws, so they took the trim off and tightened everything up. Vibration gone - until a couple of weeks later and then it came back with the odd song. ACDC Honey roll and a Didge song by Jamiraqui were the test songs that made it rattle. So, I pushed a few times over the next few days on the trim (top rear corner of speaker surround) and it stopped. Seems like it wasn't the speaker, but the door trim.
Hasn't come back since and I now regularly play at 30-35. I must say this is the best sounding OEM stereo I have had in any of my vehicles. Absolutely love it! The subwoofer does rattle the number plate though, but a couple of screws should fix that. As you do, I play my music from the USB. Recordings on the USB are in WAV file format, so no compression at all.