My sis has an 08 Tl. The car is stock w/ no mods. Had it for about 3months now, no problems until now. When she starts the engine the horn honks twice as it starts. Weird. Can someone help me out wit this problem?

 

is she engaging the alarm? If you get into the car, close the door, and press "lock" twice, it will engage the alarm. Now if shestarted it, the car may feel as though there is a theft in the car, honk the horn.. then realize the key is in the ignition and is turned passed "ON", it turns off.