the grill is the i/r sensor for the alarm. roll down your windows and alarm your car wait one minute or so for the alarm to fully arm and reach in the open window. This is a fun test to do if you are a minority in a public space (not)
Hmmm..... I left my window down and armed the alarm with key. Waited like 2 to 3 minutes thrn stuck my arm in the car and waved it aroud. Nothing happend! was on my way to work and didn't have enough time to play with it any further. Wonder why it did't work!?! Read thriugh owners manual and it said the same thing you mentioned. Guess I'll mess with it later this afternoon.