The stock horn is in the left front area. It is very cramped there due to the PZEVs cold air intake and filter box.
What a coincidence, the old whimpy horn is the same brand as the LOUD new ones!
After some testing, later put the old horn back in and hooked up also. The reason is because the chirp from arming the alarm is too short to blow the air horns. The compressor for the horns takes a little time to get going and the chirps are just too short to get enough pressure. I wanted to hear the warnings and status beeps. It still sounds great even together with the old horn. You can barely hear the old one through the extra loud blast of the new ones!
I'm a middle aged guy, with a middle school mind.