I have made an Aero Disc, feel free to edit or change whatever.

Things to note: -The complete disc is 350mm in diameter and the photo used has a 17 inch wheel (18.5 inches in diameter)

• Each disc is separated into 4 parts for easy printing on an Ender 3 (which is what I use)
• When assembled, there will be groves in between the parts that allow for plastic welding
• the retention is for a 4x100 lug pattern hole (for those of you who have universal wheels, this makes alignment easier)
• the lug stud retention thing is 20mm in diameter, electrical tape should be added to make a snug fit in the lug hole. Longer studs may need to be designed for specific wheel dimensions but fusion 360 is free and easy to get the hang of.
• I will probably also use zipties around the holes to my wheel spokes.