DarthHobbit

It is oftentimes around 20 degrees when I leave the office, so I would like to turn the car on and leave it running with the keys inside while it warms up (I have the key code access on the driver side door so I'm not worried about being locked out). But no matter what I do I cannot get the doors to stay locked when the car is running and in park. Am I missing something or is this a "safety" feature? Any way to get around it if it is a safety feature?