Agree on the 6 horns idea - that's the way to go if you can find mount points. Use the existing OEM horn wiring circuit to power the relay on/off for the Cadi horns. Then wire a new custom horn circuit direct from the positive battery post the relay post that powers the Cadi horns (with a 20-30 amp inline fuse on the wire between battery and relay). Make sure you get a relay rated for the amperage.

Years ago I knew a guy (friend of a friend) that had mounted a steam ship horn on the front of his Coupe Deville. He had it powered by two high pressure 72 cf scuba tanks mounted in the trunk. If you were in front of that thing when he hit that horn you were instantly up in the air and flailing...it was something to see.

 

Today, I installed the C and D note horns. Coupled with the two Lexus horns makes for a fuller more robust horn. I'm very pleased with the outcome. The wiring diagram saved me a lot of time!

 

provide us with a video?

 

I'm a bit late to your reply, but better late than never. It's definitely a lot more louder in person, a cell phone can only do so much in capturing how loud it is.

 

Wow, that is loud. Almost like a train, loud.

Good job on finding a solution for your problem, and thanks for posting back.