Six weeks ago I had a concept 300 unit fitted to my WRX. All seemed fine until about three weeks ago when the siren started to emit a noise that sounded like a geiger counter! It happened when the alarm was set or not.
I contacted the supplier who suggested that due to the copious amounts of standing water at the time, I must have splashed the unit and got it damp. Don't worry he said, it'll dry out soon. And as he said it appeared to sort itself out.

Last Friday night (yeah, its taken a while to write this)I was at a mates house and his wife said that my alarm was going off. So I shot outside to reset the alarm. This is where the fun begins....Couldn't turn off the bl***y siren!
The final act was to get my mates brother to wrap the siren in cloths and me and my mate to locate and disconnect the feed to the siren! About twenty minutes later the siren stoppped sounding and I drove home extremely pi**ed off. Went to the dealer the next day and went off the wall with him and, thankfully, he diagnosed that there was in fact a fault with the siren unit (no....).
It makes me wonder why a company such as clifford make these units, which ain't cheap, and they aren't waterproof. Surely its not such a technical task??