I use Turtle Wax (Finish 2001) Liquid Car Polish to remove the #2 off the roofs of JL Firebirds. Its a flat surface, Doesn't work for the Bird emblem on the hood because of the raised hood lines, It will take off the main body painted surface on the lines.
I just put very little on the number it self and let it dry only a few minutes then lightly rub it off with a soft-cloth and I keep repeating this till the #2 disappears. The result is fantastic can't even tell it was ever there.
Look at other members replies first because I am sure they may have a better way. I just know that this method worked for me many times.
I don't see why it wouldn't work on the 100Av,emblem also.