With Audi now involved with this emission scandal it could cause a drop with other companies that are in the VAG group. Skoda a notable one because their cars are pretty much re-badged Volkswagens so I'd be surprised if their stock doesn't dip in the coming days. As for recovering, well climate change is a strong point at the moment so I can see this thing being drawn out for some time. Until the end of the year at least? Maybe next year?