Unusal 2nd siren

I have an unusual request.  Maybe you guys can help. 

I'm sure you guys have seen me posting recently trying to get my Clifford alarm system figured out.  Well one of the boys at my firehouse just got his truck broken into.  His alarm went off but nobody came out cause we were all at a fire.  Work in miami so car alarms are normal.  To remedy that I'd like to install a mechanical siren, like the ones on the fire trucks, but here are my criteria:

1) I want to set it up so the siren will go off when the alarm does but not from the arm/disarm.

2)I 'd like to wire it with a switch so if I am at work/public before I exit I flip the switch and if the alarm activates the mechanical siren will kick in.  But if I'm at home(condo) I can flip the switch so if the alarm activates only the alarm's siren will sound.

Sounds kinda funky....any suggestions???

Depending on the model of clifford that you own, you should have one or more "speaker" outputs that you could use for this.  They will not output during the arm/disarm chirping, but signal is received when the alarm is triggered.  They're used primarily to run a relay for an additional horn or siren.  There are two such wires (brown) in addition to a horn wire (yellow)on my Avantguard 5 and this is in addition to the battery backed smart siren.

Tapping into the smart siren likely wouldn't work anyway, because these units communicate with the alarm brain digitally (usually through the cliffnet digital interface).

You should have some kind of horn output wire that you could split and use to power a relay that would trigger multiple horns and/or sirens upon alarm trigger.

Good luck!