If you want to beef up your electric under the hood snail horns get the five inch Hadley electrics in hi and lo tone and replace the ones you have. They give off a very respectable beep.
I installed a Viair constant duty compressor 150 psi and a 2 1/2 gallon tank, and some abs horns from Hornblasters. They were less than $100 and they are loud. I save them for rude motorist (seen any lately?).
I have other uses for the tank and compressor which set me back more than the horns by a long way, however if you got the air you may as well have the horns. I can switch between the horns when I want.
I do all my own stunts
03 Dolphin LX 6355, Workhorse W22, 8.1 vortec, 04 CR-V, Blue Ox, Brake Pro----Norm, Barb and
Doc(He's a PhD)