Theft alarm system on 575M help?

I,ve searched the site for help on identifying the beeping sound (different from the normal chirps) that seems to be comming from the alarm siren located (I believe) below the right front head light on my 575. It started after sitting in the garage for about a week. It begain as hardly audible progressing to distinctve (but not loud )over the last four days. Its periodic, but constant. I can, and have driven it with no problems making sure I had no other alarm indications. The main battery was charged and OK. I've hooked up a battery maintainer and the sounds keep going on.There is a lot of info on the site that tells me that this is pobably an alarm that indicates that the "back-up" rechargeable batteries mounted in the siren are going bad or are failing to charge. The reasearch tells me the fix will be to replace the siren or the rechargeable batteries. I want to wait untill my next service in Jan. to do this.The help I'm looking for is:

1)- Am I on the right track ?
2)- Is this sound being powered bythe main car battery or the internal siren back up batteries?
3)- Will it evnentualy quit or die out on its own?
4)- If not,any way I can stop it in the meantime?

Thanks for any help in advance.

George