+1 for Betalink being a royal bitch to work with.
The hardest part was trying to squeeze a consistent bead out of the retarded nozzle attachment. It got clumpy on some areas and too thin on others.
On a positive note, it was easy to clean up with the solvent, except for some areas in the center (recessed area on the front of the spoiler). Also it's rock solid and stable. I originally had it mounted with 3M tape, which always made me worry that it would get stolen.
2011 E92 M3