Chrome: Turtle Wax Chrome Polish works well, Collinite works well. The objective is not to use any product that would create scratches. Chrome is only a micro thin layer to protect the shiney nickel plating underneath. (I used to be in the chrome plating business year's ago before the EPA reg's got so restrictive)
Aluminum: depends on what level of aggressiveness you are seeking. Wenol Blue/Red or Simichrome are pretty aggressive. Mother's Billet Creme or Meguiar's NXT Metal Polish are the least aggressive.
Toto