I've never heard my own car from the outside, so I've always been curious how the MPE sounds to others. (other than a valet starting up and rolling it forward 3 car lengths for me) Thanks for posting these videos...they are some of the better drive-by videos demonstrating the MPE, they will definitely be more helpful than all the stationary revving videos for people trying to make a decision about the exhaust...an engine exhaust note sounds completely different under load.
I wish the the F30 MPE was a little bit louder like the BMW Performance Exhaust is on the N55 E90/92 (below); I just heard an E92 PE in person under hard acceleration the other day (similar to your first video) and it was much louder...right on the verge of being TOO loud...but sure sounded good. (Don't get me wrong, the F30 sounds great too...just not quite as a aggressive as the E9X PE, but that's probably why many people like it)