Hello Hobbit,
in all likelihood the mirror-kit is fitted in your Altea ... but sometimes, there is a need to additionally readjust the seals around the doors upper part ... or, in some cases, even bending/adjusting the doors a little helped to get rid of most of the still remaining wind noises.
Thanks will have a word with the dealer about this and see what he suggests. Assuming he is aware of the kits in the first place.
Need to get it booked in sometime soon anyway to get the 'stuttering' problem at around 50 - 60 mph caused by the ECU mentioned before on here. So hopefully get both sorted together.
Cheers