This is the buffer I was talking about,I'm polishing aluminum in this picture. I would have a clean pad on it for a white trailer.

Mine is a very old air buffer, an electric one would be better. I have been using this buffer for over 15 years and have done entire 28, 32, 40 49' race trailers and tanker trailers at work many times. You get good with it.

This is what you need for a trailer to keep it nice, no way around it unless you do it by hand.
Nothing you spray on it is going to give it the polished look like when it is new.
I'm using it tonight as I type this, right nowon my RV wheels.