Sounds like dealer talk - if they all do it, it is not a fault
I have trouble with my roof as well - but that is on the house, as workmen replacing windows have cracked some tiles and felt and now I have water coming in through the ceiling into the hall :x
Sun's come out here now after 24 hours of continuous rain. Water is still coming up out of the sewage covers in the road, flowing down the road and off into the rain drains. How does that work?
Still it gives my roof motor a good test as I took it out the garage yesteday for some room and its been stood in it ever since. Good news is it just cycled up and down perfectly on the key from my office