This happened once to myself a couple of months ago, and just tonight while my wife was driving the car. The master warning light comes on (triangle with '!' inside) and the message "KEY DETECTED IN VEHICLE" while driving, and the key is inside the car. There is also a beep and my wife claims the interior lights were flashing. I found the warning message on page 512 of the owner's manual describing situations when the key is inside the car and an attempt is made to lock the doors. But I don't think anything like that was happening when the warning came on. I've read somewhere in this forum that water running down the handles could activate the SKS, but there was no water or moisture present. Plus I've driven in the rain and no problems. I don't know. My guess is that this "problem" is more of a nuisance rather than something serious/dangerous, but should I be concerned? Has anybody else experience this with their car too, or is it just us? Any thoughts/ideas as to what might be the cause?