Two of my half-moon 'racing' disks went missing this year, before I took the other two off and put them in the trunk. The reason is that I got some snow tires on some new rims in November, and the steel rims in question were a loose fit. I didn't notice when I put the racing disks. Are pizza pans more aero than half-moons anyway? It seems like the extra dish in the half-moons is undesirable to my 'aero eye,' but it's easy to be wrong.
It took a while to source some pizza pans that were cheap enough for me. Walmart had 16" pans for $3.8 ea, but I want 15-15.5" for the R14 rims. Eventually found 15" on ebay, $20 for 4 w shipping, i.e. $5 ea.
I also got some hub caps from Walmart. I got the ones with the least dish, but the pizza pan dish was a much better match to the OEM hub caps.
Put jack nuts into the OEM caps:
The reason I initially didn't want to use the OEM caps, the winter rims don't have the same dish as the OEM rims, such that the OEM lug nut retaining rings don't fit the hub cap on the winter rims. In the end, the answer was zip ties:
Finished product (I have 2 of these done, need to make 2 more eventually):
For now I have to remove the 6-32 phillips screws and the pizza pans to get at the air valves, but I'm thinking I might cut a hole for the valves and apply some cover, or just tape.