(Nitrogen-fertlized grass on left, native habitat protected by carefully-managed grazing on right.)
This is more of a marker/prediction: we'll be hearing about the environmental effects of VW's illegal NOx emissions. Atmospheric NOx emissions are a big deal in California, as they're accepted by wildlife agencies to be something that kills endangered species by replacing their native habitat with NOx-fertilized, invasive rye grass. You can't do that without a permit under the Endangered Species Act.
I spent quite a few years working on a permit system for a Habitat Conservation Plan in Silicon Valley. Development that causes vehicle emissions is allowed because it's mitigated for, based on expected (legal) emission levels. Actions like illegal, unpermitted emission are not protected by the permit that I personally spent time on - VW is actually interfering with our solution.
I think all NOx emissions not made pursuant to a Habitat Conservation Plan permit in California are in a legal gray area (at least), but completely illegal emissions like VW's are unquestionably illegal. Solving the environmental problem needs to be part of the overall solution that VW provides.
And as for allergies - guess what rye grass does. This health impact hasn't been included in estimating how many people have been hospitalized and killed by VW, as well the number it will keep killing in the year or two the company estimates it will use to fix the cars instead of replacing them.