https://flic.kr/p/HKPqfb
If you look at mine that was torn off, you can see the holes underneath where it wraps under and is attached to the frame.. Those Self Tapping screws come loose, the aluminum skirting starts moving/working and makes the holes too big and it comes off and in my case gets torn off before I noticed that it came loose. Was driving home from Florida in a snow storm and didn't see it flopping as the wind was blowing up against that side.... New one on order, scheduled for replacement along with new black tank that is cracked on May 8th at dealer...