Besides being electrically more efficient, loud electric horns will fit the look of your HHR better also. I would hit up a junkyard for an older buick or cadillac horn - those puppies were LOUD!

 

You make it sound like I need an 'Ah-Oo-Gah' horn. :)

I figured on the Hi/Low like Fiamm (small and nicely painted).

Since I plan on building a project car I can still put these air horns to good use in the future (hopefully soon).

 

Now I am getting ready to give up (not really). I bought a pair of high/low horns. The wiring shows a 10 amp fuse, so I tried hooking one up directly to the fuse box, and still no sound. I did it quickly, and will try again. But something is definitely not right.

 

Sorry for bringing up old posts but I hid my air horn in my wheel well by my stock horn and used the stock lead to power a relay that runs my horns. Hit the horn button and they both go off!

 

I'm planning to add 70's Caddy 3 horns set-up to mine.