Sorry for the bad photo-chopping; I'm forcing myself to learn GIMP 2.8:
You will need a stiffening bead or rib at the bottom of your sheet material. Given that you could curve the edge up and in abaft the wheel centerline.
Those three dots?
Dzus fasteners on tabs riveted to the lip.
If you cut your material out of an old car top you can get compound curve for free. It will catch highlights better, flat skirts and moon disks look funny.