Yeah, I was thinking of getting supertones, but the other choice is to get...
It's a 139 dB horn (MUCH louder then hellas) that also flashses your headlights when you use it...but you can still use your stock horn.
"If you press the horn switch briefly, only the regular horn is activated. Pressing the switch for ¼ or ½ second (depending on a switch setting you can choose), causes the logic in the control unit to now engage the raucous air horn and high beam lights. When doing this, it pulses both the horn and lights for even greater impact - as shown in the video. You can also set the loud horn and lights to not pulse if you prefer – there is a switch for this too.
Watch the video, it makes more sense. I think it's worth the extra $35...
So you are willing to wait that 1/2 second for your louder horn to work? I could see the 1/2 second to get the headlight to flash, but the horn part is silly. Just get the supertone horn set and you have loud horns all the time, and can still 'toot' at your friends.