I'm usually walking away from my car when I lock it with the key fob. That said, I don't see the lights flash. If I hit it twice, the horn will blow. I don't like the horn blow. I would like to make another sound, maybe a horse winnie. I assume I would have to buy a 2nd horn, possibly one of those that have dozens and dozens of sounds. Also, I assume, I would have to tap into the wire that the key fob lock is on, maybe the one that blinks the lights. I guess I have to find a wiring diagram for a 2007 and or a set of car alarm instructions for the same.

 

Even when I had a V6, I would turn and look at my beautiful Mustang several times after I parked it.
I would suggest you do the same.
Hit the remote during those looks.
You will then be able to see the light.
Seriously, the easiest way to do what you ask is to wire the sound maker you want to the horn power wires and put separate wires to the horn from a new button on the dash.

 

If I'm walking away from the car, what does a button on the dash do?
Yes, I often look back and say "Oh Baby", but sometimes I'm in a hurry and forget to tell my sweet thing, I love you.

 

I grew up listening to these - If I could squeeze it under the hood, I would! I had a two-tone set in the Galaxie, but it had tons 'o room in the bay and it was a simple hookup.

True Story: I was going through New Orleans coming to the railroad tracks and I smashed the air horns and traffic on both sides stopped short. What I didn't realize was a train was coming fast and blowing at the same time I was so I didn't hear it - it was a **** close call.

 

The way he described it, the sound you want would go off when you double lock your car. Re-wireing the horn to a new button on the dash is just in case you ever need to use your horn again while you're driving.
lol, pretty funny. But are there no lights/gates when a train is coming?

 

The button on the dash is for the original horn. In my state, you must have a horn. It is not important which button activates it.
Easy, but perhaps there are better ways to to it.
Myself I use my horn way too often to have it hooked up to a separate button.

 

I always look at the lights, or just lock it when you shut the door so you can see it lock or hear the click. I absolutely hate to hear the horn just to know if it's locked.

 

I guess I'm looking for an alarm feature without buying the alarm system. I had Viper alarm installed on my 89 LX 5.0 and it of course made the chirp sound. Now I'm not a fan of the chirp sound, they are like opinions, everybody's got one. However, I would like it to make a sound when locking and the lights flash. Something more than the lock "plunk" but not as annoying as the horn.

 

Not at the crossing on St. Claude in the Ninth Ward - not in the 90's at least.