That is what I heard, over the phone, from a couple of dealers in Europe as well, but I could not leave it like that.
I was able to personally visit one dealership in Poland yesterday and after spending 20 minutes explaining what I am after, their answer was that it comes as a whole kit and only with a brand new car
So I asked them what happens if someone were to order a new car with the kit and then later on came back to them with a broken wing due to accident or whatever
Fortunately their parts manager was a friendly guy and started scanning the database, we have found the aero kit parts and I was told I can order them separately. My main interest was the wing and I got a price quote for it.
Sorry for derailing op's thread into the aero kit discussion