Something simple would be a nice round piece of white vinyl decal

 

 

You can double up on the decal. That should do it?

A good quality decal, with a proper mil thickness, should not be translucent!

 

I opted to repaint the entire bumper to cover the holes (picture taken before priming) :

 

I picked up a small plastic plug (less than $1) from the hardware section at Lowes. Coated the plug with touch up paint and then installed after it was dry.

 

Vinyl always worked for me.

 

Nice wheel and tire setup man! There are some shops that can fill that hole using a mix of plastic puddy and some kind of screen material behind the bumper. Then, they can blend the paint into the oem paint to keep from doing the whole bumper.