2003 VW Beetle freak window problem?

[Hypergluco]

A friend of mine has a hard top 2-door 2003 Beetle which hasn't given her too many problems so far. On Sunday, we parked it with the windows up, and the following morning both windows had completely lowered themselves. I understand that VW remedied window regulator problems prior to releasing the 2003 model so that shouldn't apply here. But for both windows to roll down spontaneously is freakish. The car doesn't even have a single button to control both windows, so it can't be a problem there either.

I'm loath to send the car for repairs as the windows still appear to function perfectly well, and the dealership will undoubtedly bluster and bullshit their way through replacing the entire mechanism at huge expense.

Any ideas?