help removing tarnish from metal spare tire cover

[Julesh]

I have some nasty stains on my spare tire cover where the metal is. I think it is chrome? I am using some Mothers metal polish and it seems to be working... slow progress though. Am I on the right track here or is there a better product I should use? I tried to take pics but as you can tell they arent the best pics. Thanks in advance.
http://tapatalk.com/mu/c6e4c31f-7077-36b5.jpg
http://tapatalk.com/mu/c6e4c31f-7055-2836.jpg

[ohmy34]

A lot of those tire covers are stainless. It will polish but you will need to get agressive with it. maybe a drill with one of those mothers powerballs. jonathan