Tony, this is why I want to upgrade my stock horns. This story comes from one of the big-rig/trucker sites I browse through on occasion...
"Anyway, there was a "BlueHair" hogging the fast lane and she wouldn't get over. Gave her 3 chances for about 2 miles to get over,while the other cars were passing me on the next lane. We passed under an overpass and that's when I unleashed the Grovers vengance. Needless to say, she moved over and let me pass and shooting me the bird when I went by. I guess the bird was justified."
"Grovers vengance" is a brand/model of air horn that the discussion was about
I've been pricing and find between $150 for a basic kit and $550 for the full 'blown' train kit