Optimistically, in the remote chance that September and October in Napa will be somewhat meteorologically normal, the folks at Opus One have treated the south-facing side of their vines, in one block of their vineyard, to guard against damage to the ripening grapes. It was 99 degrees F in my neck of the woods today, so maybe they know something I don't.
Surround WP crop protectant forms a barrier film, which acts as a broad spectrum protectant that may decrease damage from insect pests, but more importantly as a protectant against sunburn and heat stress on grapes. Surround is made from kaolin clay, an edible mineral, used in toothpaste and also as an anti-caking agent in processed foods. This product is apparently acceptable for use in organically grown vineyards. Whoop-de-doo!
It may well work, it just looks weird.