Simichrome Polish , I've been using it for years and will swear by it . I have a set of American polished aluminum wheels that I bought in 1978 ( on a daily driver ) and they look brand new ! If you use it a lot of it a tube will last several years .
You can find it at you local bike shop ( motorcycles ) or on line . If they try to sell you Flitz Polish don't by it , it's not the same .
It also removes scratches from plastic windows and does wonders for BMF !