Often when I shift to P, I get a loud beep noise for about 1-2 seconds. I can't for the life of me figure out why. Looked in the manual and couldn't find a reason. I thought maybe it was because my seat belt wasn't on or maybe because I didn't come to complete stop. But I was able to rule those out. It has happened when I've been wearing my seatbelt and when completely stopped. Anyone know what the beep is for?