Coroplast wheels covers ?? I thought you wanted this thing to be "stealth".
Hmmm.... just my opinion, but that's really going to make the car look like .........well not nice.
It's too bad you can't use clear Lexan ( the strong stuff ) because your wheels look great.
( The draw back is that you would have to keep the inside of the wheel clean often. )
You could also go with flat black and leave the trim ring area the color of the wheel as seen here :
Personally, I think a sheet of flat black ABS would look
much more professional than coroplast which has noticeable ridges and edges which look odd.