[Rey]

Paint has been wearing off the radio buttons for years now, and GM has not done a "fix". Their remedy is to warranty the radio which in turn is sent back to the factory for new buttons. A new reconditioned radio with new buttons only delays the problem until probably past one's warranty.
I did a fix some 35K miles ago, and there is absolutely no flaking whatsoever. I believe the problem stems from the lacquer paint used by the factory. There are trace amounts of salt on one's fingertips just from normal persperation, and over time this seems to break down the paint. The fix I did was to remove the radio and the buttons. It is not hard to do provided you have the factory manual. I then sprayed the buttons with a rattle-can spray of polyurethene "varnish". The new coating is not detectable.