My A4 SE has developed an odd problem!

First of all it opened it's own boot lid while left parked on two separate occasions. The dealer looked at it and found no recorded fault and couldn't find any obvious problem, they reset the central locking and adjusted the boot catch.

Yesterday after several weeks interval since the previous incident, the car did the same again, while standing outside the house - however this time it also opened both front windows fully!

This is an obvious problem in that I don't feel confident to leave the car parked in a street or public car park, which I have to do regularly and also if it opens up in heavy rain the interior would get soaked.

It's back with the dealer, again no faults showing. they are keeping it for a few days to investigate thoroughly and hopefully get to the bottom of the problem. I wondered if anyone had encountered a similar problem and might be able to suggest a cause?

PS I've been lent an A6 Avant - wish my car's steering was as good!