Advanced Engineering Tech - Electrical question about multiple horns

Let's say my friend is disappointed in the sound level of the horn in his z28 to get the attention of left lane loiterers. Let's say he has a couple of parts cars around to strip horns to wire in addition to his camaro horn, likely in series or maybe in parallel.

I'm thinking maybe I'm best off wiring my own whole new circuit with heavier wire and run three horns in parallel all to a new button installed in my interior? I'm no EE, any advice for me?

Hmm, maybe I'll hook each up separately with it's own button and then I can push them all at once or musically to my content.

Maybe there is a better category for this question...

use the stock horn button to run a relay wire the relay to power the horns from the battery

Google "train horn". There's people who live for that
stuff.

yeah I've seen that, not what I'm looking for, just something a bit more noticable than my barely audible horn.

I've saved every horn from every '60s and '70s beater
I ever junked. Full size used to have decent horns.
And you can tweak the freq some with the screw.
Get a pair of same-tone ones and tune them to a
nice epilepsy-inducing 8Hz beat note. :kali:

you can't connect them electrically in series.
you need to connect them in parallel so they all see 12 volts, because they require 12 volts to operate.

simplest thing to do is remove the + wire that goes into your current horn and put it into the control side of a 20A relay. The other side of the control goes to ground. Then use 14ga or 12ga wire from fuse box bus bar or battery + to one side of the switching side of relay, other side branches out (in parallel) and goes to each + terminal for each horn.
You can pick up a 20A automotive relay from radioshack for $6.
And you should put a 20a fuse inline between battery + or fuse box and the relay.