I designed this to replace one of the screw in wheel caps for Rotiform wheels. It just presses on the hub. It will help protect the threads and hide your rusty nuts. 

Its definitely not as good looking as the original nut and plate, but since those are quite expensive to replace when they fall off or get stolen, I figure this is a good alternative for daily driving.  

For printing, I would suggest splitting it apart in a slicer then printing it as two parts and using CA to hold them together. That allowed me to paint the caps separately and keep the part that goes into the hub the correct size and help keep the threads clean of paint debris. 

Due to possible heat, I used ABS, but any other heat resistant filament will work. Just watch out for shrinkage with PETG, had a set fly off because I didnt account for the shrink lol.