The audible warning takes the form of a series of beeps possibly a dozen. Sometimes the vehicle drives for 100s of miles without the warning beep, at other times it makes a series of beeps. Then the beeps stop and then there is another series. This repeats for a while. Then it stops randomly. There are no warning messages or lights on the dashboard, no indication on the dashboard that any doors are open and no other observable pattern in the occurrence other than an unconfirmed possibility that it may be more prevalent in the wet.