...this would be a huge blow to the VW brand/reputation.
Everyone wanted 40 MPG cars. Hyundai/Kia made "procedural" errors in testing caught by the EPA. Fine was $300 one year ago, Did sales drop? Hardly they went UP.
One year from now no one will care or remember. They are all too busy taking pictures of their food and posting on FB
To the extent Porsche owns part of VW, the value of those Porsche assets could drop and could possibly become zero. To the extent VW owns part of Porsche (I'm not sure who owns whom) VW could end up selling, or in effect being forced to sell, its interests in Porsche.
VW AG owns Porsche AG along with Bentley, Bugatti, Audi, SEAT and other marques. That company is now being broken down into 4 holding companies of which PAG leads Bentley and Bugatti. Porsche SE, a holding company holds 51% of VAG stock effectively owning VAG
Nothing is going to happen to Porsche AG, the auto making company. 99.9% of the public has no clue how convoluted the companies are or who really controls what. I can believe the chair of Porsche SE, Wolfgang Porsche, looking up vertically, has no idea about VAG daily operations nor the PAG CEO, looking horizontally. But SOMEBODY in the VW manager chains has to know.
As to civil liability. What did the 1,000,000 Hyundai and Kia owners get? A tank of gas?