The bottom of your front quarter-panel collects debris.
Not sure if this is a problem with NB and NC models, but it certainly is with NA.
There are 2 bolts that are either 12mm or 10mm (Tez's Clubman had 12mm and my povo-pack had 10mm) on the underbody just infront of the door seam, and 2, 8mm/phillips-head bolts in the wheel-well.
Undoing all 4 will allow you to leverage the bottom-rear part of the front quarter-panel.
Get an ice-cream container, place it under the seam, and pull the panel back a few cm.
Long story short, I managed to fill 1/8 of a medium size ice-cream container with debris that got collected in there.
Good tip to help reduce the chance of rust.
Very easy to do ... so do it!

Thanks Terry!