center caps for enkei rpf1s???

[andruboz]

I am tired of looking at the rusty end of the front axle bolt.

some websites say they have rpf1 centercaps and other websites say Enkei doesn't make center caps for 15's. only for 16-19's.

and they retail for $25 a piece. too much.
I tried the caps that came with my Kosei wheels - didn't work.

So I thought maybe I could put a big chrome acorn nut over the end of the axle. but without a hole for a cotter pin, it will eventually become a projectile.

anybody have a cheap solution for a center cap?
only need 2 for the front. the back isn't so ugly.