Question On Replacing Aveo Horn w/ Aftermarket Horns

[Steve_Hewlett]

I have a 2007 Aveo5 SVM. The horn needs to be replaced. I want something a little louder and found these horns:

Loud 12V Two Air Horn Snail Set Dual Twin Tone For Cars Bikes Vans Boats 120db - US$12.84

My Aveo has a two wire connector that plugs into the single horn. I need a relay or something to plug into that would split the power to both horns. I found this relay on the same web site that looks like it would do the job, though one review said that the wiring pattern on the relay was reversed:

4 Pin 12V 30A Relay For Car Automotive Boat Van Motorbike Lights Horns - US$2.00

I think I would also need some wire connectors with spades to hook everything together.

Has anyone done this - replace the single horn with dual horns - and how exactly did you do it? Please include URLs for the parts needed.

Thanks,

Steve

P.S. - I just came across this single replacement horn which looks like it might work well - just plug it in in place of the stock horn:

http://www.amazon.com/Chrome-Grille-.../dp/B00Y5EZ4R6

Any thoughts on this horn?