I'd like to purchase a loud air horn that wouldn't require much in the way of power past what I have stock ( I want to wire it to current wires but get louder response), this is not for my Mark but for a beater car I drive to work and back. I get so annoyed at other bad drivers that I want to startle them with a nice loud air horn, any good suggestions? I don't want to build a pump in my trunk so.....