massively overpriced for a alarm siren....that is just a part, obviously they would want extra for replacement...going to maplin tomorrow....they have 3.6v batteries, I will get 2 and connect them in serial to create 7.2v what is what the siren needs...going to take the old battery our and replace with new ones...will post some pictures while doing it so maybe it will help somebody in future...wont be a hard job I believe done the same on Audi TT, the only difference was that the TT was not fussed about the siren not working...my car developed numerous problems since this happened....also one thing to mention, last week was the first week sicne I own the car when i did not use it every day, just twice for a short town run...I believe this was also a contributor to the battery pack in the siren to discharge fully.....had the car on for 2 hours idling in work to try and charge it back up but without luck = needs new battery pack....another thing to mention, my alarm light is constantly flashing even while i am driving, also the hand break light is constantly on....apparently all symptoms of a battery pack in siren being bad....