How do you guys keep your polished aluminum...polished?

I was just sitting here thinking about how much time I have invested into polishing my valve covers and air cleaner.....plus my carb is nice shiny aluminum aswell.

on hot days my engine block builds up alot of moisture on it sitting in my garage and I see more and more anywhere I have polished aluminum on the engine is starting to show signs of oxidization .

on my final pass of polishing when I polished my parts I used mothers aluminum polishing compound.....but its obviously not deterring the oxidizing any.

are there any special tricks you guys use to keep you polished aluminum parts free from oxidizing?..

maybe repolish them back to a nice shine and smear a light coat of wd40 on them? or?

any tips or tricks would be appreciated, thanks