How to get super glue off car mirror?

Okay, I have a 2009 Silverado with the black plastic mirrors. I bought the chrome add on pieces and they came with 3M adhesive tape already on them, well they didn't stick very well and I decided that I would super glue them. Well now I want them off, so how can I get the super glue off the plastic? I get the chrome off but the glue spots are still there. I've tried acetone, rubbing alcohol, Nothing worked.