So about a month ago I'm driving along listening to my iPod. All of a sudden A loud Pop/crackle sound happens at an extremely loud volume and proceeds to scare the living **** out of me. I lost all audio after this. Switched to Sirius and FM with no change. I muted the system and unmutued it with no change. I powered off MMI and powered it back and everything returned to normal.
Flash forward yesterday driving to work listening to Sirius Radio. Same exact scenario except the loud pop/crack happened twice before losing all audio. Same attempts to fix it and had to power off then power back on MMI (press and hold volume for a few seconds then).

I always listen to Music volume around 9-14 nothing incredibly loud unless my windows and moon roof are open. Even then i never max out mt volume. My bass is usually +1 or 2 over the norm and no other crazy audio settings.

Any suggestions or ideas as to what the malfunction is or how I can fix this without having to go to my local shop?
I have a road trip back to NY Tuesday and returning next week which will give me 709 miles/ 12 hours each way. I'll report if it occurs again