Found that out the hard way last winter. My girlfriend went outside to start my car before work to get the windshield clean and warm it up while i was in the shower. She said she locked the doors because she didn't want anyone to steal it, but it was ok since she had my other keyless. I told her that if the car was running, one of the keyless safety features is that you can't use it. Lucky me, esp. since I had recently bought the car and the dealer couldn't locate the other key, so I had no 2nd key. I had to wait over an hour for AAA to show up and jimmy open my door.
