Leebro1: The factory alarm system is adequate for the following reason only. If a professional wants to steal your car, he (they) will do it in less than 2 minutes with a flatbed and chain. They don't "break" in necessarily, they just drag it up the flat bed and away it goes. Most people would think it was a repossesion in progress. It then goes to a warehouse and is then loaded on a freighter for either South America or the Mid East. They got an "order" for your S4 most likely. The best way to protect it is to park it with a paid attendant. The local dealership had a new 528i wagon stolen right off the lot. Noone saw it and it was done before 7pm on a Sunday evening. OUCH!