Seems like there are two possibilities: engine noise is causing windows to vibrate making a sensor go off or the reverse distance sensor that uses microwave radar (X band) is causing the base unit to think a sensor is going off. It is a WRX (lots of rumbling engine noise) so I would imagine that the first scenario is more likely. A home alarm system is most likely going to be 433MHz (or even the wifi/bluetooth bands) but not X band.