Hi.
I believe it is under the nearside bonnet catch at the front of the car.
First on my list would be to try closing the bonnet by allowing it to drop from about 10" to ensure it has actually engaged properly and see if that cures it 🙂
Good luck
John
hi, my alarm keeps going off in the middle of the night, the settings screen says bonnet sensor, does anyone know where this is and can it be turned off ?