I successfully removed the warning labels from my 2013 VW Golf R. Removed the visors. Soaked a towel with denatured alcohol and allow it to soak 15 - 20 minutes. The decal peeled off easily.
When i tried to remove the labels from the visors on my 2014 Subaru BRZ, it did not work out very well. I was not pleased with the results.
I'm scared to try it on my Cayman. I think I will live with it.