I have had the exact same thing happen with my vehicle recently. It's a 2012 RX350 I've gotten the "key detected in vehicle" while the car is moving, my doors will unlock themselves and "Key Detected in Vehicle". The message stays on for a bit, then goes off on it's own. Just yesterday I got a that the back door was open, the interior lights come on & the chimes sound. All of this while the vehicle was in motion. I've noticed it happening or possibly being triggered by going over bumps in the road. Were you able to find out how to fix it?