I've tried waving my arms inside of my Boxster after I lock it with the roof down and nothing. Maybe the roof has to be up or someone needs to be sitting in the car.From Porsche iManual | 2013 -
The alarm system monitors the following alarm contacts:
If one of these alarm contacts is interrupted, the alarm horn sounds for approx. 30 seconds and the emergency flasher flashes.
- Alarm contacts in doors, luggage compartment lids and headlights.
- Interior surveillance: Movement in the interior when the vehicle is locked, e.g. attempted theft after breaking a window.
- Inclination sensor country-specific equipment: inclination of the vehicle (e.g. when attempting to tow).
After 5 seconds of interruption, the alarm is triggered again. This cycle is repeated up to ten times.