Odd Sound When Switching from D to M

Have a 2012 650 Exec with just over 3,000 miles. Tonight was the first time that I heard an odd sound coming from under the service lid when I would switch from D to M or engage the Power mode. Now obviously I could only hear this at low rpm's but I'm assuming it's doing it all the time when I switch. I wouldn't call it a grind but it sounds kind of like something being shifted from gear to gear...I know...it's hard to explain. I have never heard this before and just wondering what the Burgmaniacs think.

Thanks,
Coz