thats cosmoline. you'll need to use a solvent to remove it, off the top of my head, 90+% isopropyl or denatured alcohol should do it. if you need to get more aggressive, laquer thinner.
Past: 2001 Orientblue E46 330i
Past: 2004 S60R 6MT
Past: 2007 E90 335i 6MT
Past: 2010 335xi ZMP, BMW Performance Kit, BMW Performance Exhaust
Present: 2013 335i 6MT ZMM/ZDH/ZTP/3AG/494/508