If your lace wheel center caps are dingy and tarnished, they can be easily refurbished. This is what I did.
Using a Chore Boy pad or a glass cooktop Scotchbrite cleaning pad, I applied some stainless steel cookware cleaner.

After wetting the cap, using circular motions, I removed the tarnish, as well as the faded Fiero logo. Took about 2 minutes per center cap.

Once you have it nice and clean, follow the instructions on the can and apply some Aluminum Clearcoat to protect them.

You can leave them blank, or when they are dry, if you wish, you can apply Rodney Dickman's wheel center cap stickers to replace the original logo, or get the inlaid decals.