Polishing a pneumatic trailer

Hello. I haul bulk cement with a 2007 Trail King pneumatic trailer at work. The former driver of this unit did absolutely nothing to maintain the high luster it came with. The Magnesium chloride in winter and other contaminants just trashed this trailer. I used aluminum brightener to "clean" it and obviously ended up with the proverbial "gray" trailer. After this I used wool and foam pads with a few different polishes I have used over the years to try and get somewhat of a decent shine. It is somewhat shiny but not uniform at all. The idea of a chrome like finish would make me extremely happy but poses a major hazard in the sunlight! What would you suggest to make it look as close to the original finish? There is a horizontal grain to this alum., and I am not interested in removing this grain, just way too much work.