So gents, My rims look great all around, but you cant help but notice the nasty center caps because of this buildup on them, has anyone cleaned their center caps with something and it actually worked to get this crud off? thanks!

 

It had to be polished off, but I would try some CLR first to make sure it's not hard water

 

That looks like it might be clear coat failure.

 

What's the material; aluminum, plastic . . . ?

Is it bare, or clear-coated?

 

Aluminum and I think it actually is "clear coat failure" because i seem to be able to chip some pieces off with my fingernail..

 

Then you'll probably have to strip it to the bare metal, maybe polish it a bit, and respray with a new clearcoat. You might try some plastic polish first, which shouldn't damage the clearcoat, but if it's already peeling, that may not give a good enough result.