never had problems with wind noise on mine not even above 200.....but i know people who did.............try trimming the rubber edges so that the window fits perfectly.......sometimes the rubber is not in the right position
You have two things that you can do to stop this. First of all, take the car to the dealer and ask them to re-align the windows so they will seal properly. That normally helps a lot and it's not a big job.
Otherwise do what I do, every time I get into the car and close the door I wind down the windows a litlle and then close them again, this is a (dare I say it) BMW trick done manually, but it seems to align the windows properly and eliminate any noises.
If Alfa fitted these servos to later GTVs then there must be a part number and they must be relatively easy to retro-fit. Don't give up just because your car is an earlier model... I bet this very useful enhacement could be on your car without too much effort!!!