Strange stains/distortions on chrome strip

[voidpointer]

The photo below shows a weird series of stains on one of the chrome strips above the passenger window of my 2016 Mazda 6. I'm not able to wash it off or anything. What exactly is this? Is it permanent damage? And if not, is there a way to remove it?

https://goo.gl/photos/XwBDBEyoBNxAAJGu7

[swanicyouth]

Damage is likely permanent.

People with tell you to try this polish or that polish, but I will bet you almost anything it will not come off.

These type of trims pieces have some type of coating on them, likely to protect from UV because it's "fake" chrome. Once the coating oxidizes/fails - there isn't much that can be done other than replace the part or wrap it in Di-Noc (or similar)...

There used to be a product called "DeOx It" (or something like that), that a lot of BMW type retailers used to sell for this type of issue.

The product seems to have had inconsistent results from what I recall.

[rlmccarty2000]

Looks like corrosion. These days it is hard to say what might work without seeing it in person. Some trim is plastic, some is aluminum, basically too many variables to give you good advice. Saying that, it looks like it may need to be replaced, so choose a metal polish and see what happens. You probably won't make it any worse. Sorry.