[addy27]

Wanted to thank you for this post man, I switched up to M sport side skirts and followed your guide. BTW, I am a bit disappointed as the F10 M sport side skirts don't bulge out as much as the E60 M Sport or M5 side skirts would. Oh well, I'm still happy with them.
I wanted to add a few tips:

1 - When putting the side skirts on, make sure they go UNDER the underbody cover panel, NOT over.. stupid lesson learnt..

2- Be careful of the lone little clip/slot at the very front of the side skirt where it gets installed into the plastic trim brackets that hold the side skirts in place. Its prone to breaking easily. It shouldn't be a big deal at all but still these things get brittle over time and the driver side on mine was already broken off in the bracket. once you get to the front, you can use a plastic pry tool too to make sure you're not putting extra pressure on this clip/slot

3 - At the front, the skirt goes under the underbody panel goes first, then the front panel goes over it and then all they all get screwed down. I made a boo boo of putting the the order where the front wheel well panel goes first, then the underbody panel. And at 60MPH I was hearing a nasty flapping sound. and by the time I got home, that little end piece with the bracket for the screw got ripped off on the road somewhere.. Had to fix the order of things after getting home and now should be all good.