2009 metal kick plates

[turnerrc]

So I tried posting this before titled "door sills" I guess I was using the wrong name for what I meant. The kick plates on my 09 G37 are in bad shape. They have spotting and discoloration that I can't seem to polish out.





you can see the before and after. much better but still spots!
I assume these are aluminum, they are easily replaced, but I shutter to think of the cost. Anyone replaced these or had any success in polishing them?
thanks

[turnerrc]

Really? No one else ever had this problem. Maybe mine is a manufacturer's defect.

[biggie]

Never seen it before. There should be some polish or buffing that would take it out though.

[joe603]

dumb question...have you taken off the protective plastic yet??