If I had to take a wild guess, I'd say that the people at the Dow Jones Sustainability Index picked the winners of this year's sustainability prizes, which are awarded this September, before the recent revelations about Volkswagen . At the top of the list, winning in the 'Automobiles & Components' category, is Volkswagen AG... This seal of approval for investors who are concerned about sustainability is a big problem and will no doubt bring many to question just how reliable those ratings are, especially those that are based mostly on voluntary reporting by companies rather than on due diligence from independent third parties.