Fishing line doesn't do any damage. Any surface marring (which can happen with floss as well) can easily be removed with a little polishing compound. Took me la few minutes to remove mine with fishing line. Removing left over adhesive is a little more time consuming.
2012 MR e92 M3 DCT, fully loaded... GONE but not forgotten!
2008 e92 M3 Coupe 6MT | AW/BLK Extended...SOLD!