I used denatured alcohol on the Box. You have to be very careful not to let it get into the mirrors covers' hinges.
Some said isopropyl alcohol is safer and just as good. So when I did Mrs Sixter's X5, I tried the isopropyl. After the first one I went back to denatured for the passenger side, and it was much quicker.
The sponge was a technique I didn't think of. Paper towels probly don't work as well to saturate the sticker. Live 'n learn.
