Yes I made my own center caps. I still have the big aluminum disks with the Volvo logo on them but I wanted exposed chrome lugnuts for a sportier look.
After sand blasting them I had them powder coated in high gloss white oven/refrigerator coating. The shop that did them said this is the most heat, cold and chip resistant coating ever made. They had a chrome-look coating, but it required a second clear coat to protect it. It also cost double for that. I made the rear center caps from the plastic buttons at the end of the 24" plotter paper rolls. I just cut the edge with a knife to fit. Ok, don't laugh now. I made the front ones from TIDE bottle caps. Stop laughing now. They are a perfect fit. You just have to trim the threaded part off. You are still laughing aren't you. If I ever lose one, all I have to do is more laundry.
From a distance they look like the $1000 sport compact wheels you see in the magazine ads but cost me less than $200 including the tires too. I am running a pair of (free) P185/70r14 Cornell Euros in back and a pair of new Cooper 185/70/14's up front.
Ben