I've heard what that sounds like, and this is a much quieter, but constant rattle, noticeable if the stereo is off. Mine are from the front driver & passenger corners, like where the tweeters are in the front doors. And there is also a rattle just by the driver's shoulder, seems like it's coming from inside the driver's door--if I push my arm against the glass I can get it to stop.The only rattles I have had have come from the rear seat belt buckles when not fastened. I just tuck them between the seat cushion and the plastic side and that stops it.
I'm not in a hurry to try and get it fixed. It doesn't happen every drive. And I'm sure if I took it to the dealer, my luck would be that I couldn't replicate it then.
If I get brave, maybe one day I'll pop the driver's door panel off and see if I can see anything loose.