A couple of incidents that confirm the above:
1. Waiting behind a cager in parking lot. Cager has already passed lane (one way)...decides to reverse to position self to turn into lane (again.. one way / wrong way)...does not look back and begins to reverse. I give courteous tap of the horn. Obviously cager heard the horn and proceeded to move on...do not believe same would be said with stock horn.
2. Coming right off of freeway...slight bend coming to an intersection (NO STOP) so you either go right or left. Cager slows to stop and I can see cager talking to passenger deciding which way to go. Meanwhile I'm thinking...what a way to go...sandwiched between two cars...I lay into the horn...cager starts moving. Finally catch up to cager...sees me in her rear view mirrow and get this...pulls the sides of her hat down over her ears...well at least I knew she heard the horn.
Initially I was concerned about doing the air horn mod....now I find it to be a necessary safety device...a real horn.
Note: In both incidents, I did not behave in a manner that would have been construed to be confrontational...just a "wake up!".