I agree with Bugnatr about lane splitting.
On Saturday I had several miles of splitting, followed by my son, me on my near-silent FJR, him on his Ducati Monster. The Monster is NOT near-silent.
Had to stop for a narrow gap, driver in one lane having stopped his car pointing into "my" lane. Rev'd my engine (having selected neutral, got to watch these YCC-S things), not a reaction. Son, behind me, revs his Duc; car driver jumps into alertness, can't get his car out of the way quickly enough.
Loud pipes may or may not save lives, but they certainly get you noticed.
Ps. I won't use my horn in these situations, but that's part of my personal lane-splitting etiquette.