It looks good, especially for a first attempt at airbrushing. I hope, when I eventually get my airbrush, that it will look just as good.
But I agree a bit with TankCarl. The whitewash seems a bit too clean. Ofcourse weathering will probably dirty it a lot. Yet, IIRC much of the whitewash used by the Germans was of such a substance that it gradually came of over time, quite often needing redoing during the winter. And the places where it first came of would be at the edges. Also, it was usually put on in the field, which often can lead to an uneven finish.
Anyways, that is my two € 0.02 . Congrats with a so far great looking model.
Harm