I was told by my local installer that additional components can't be added to our Subaru (upgraded) alarm because there are no spare connections to connect to. Keep in mind that their shop has only installed one alarm on a WRX and he couldn't be too specific about why...
Also a larger siren/horn can't be added because it may draw more power than the stock one.
I know it's possible that the guy is just trying too get me to buy a new alarm.
Does anyone have any proven info regarding adding components to a stock (upgraded) alarm for our WRX's? If so...How was it done?