Maybe you can get your (illegal cheating) car replaced for a new one.
In the aftermath of the VW group (incl Skoda,Seat, Audi, …) there have been at least two recent verdicts in German courts ordering the company or the dealers to replace affected vehicles. The most recent one (which of course will be appealed) said there should be no deduction/charge for the kilometers already driven. In other cases each 25,000 was deemed to equivalent to 10% of price. Apparently VW is playing for time in Europe as the is a very short statute of limitations on this kind of case. I don't recall whether it is the end of this year or the end of next year.
Put this in a search engine "VW Group ordered to take back emissions-cheating Skoda by German court" or click here: http://europe.autonews.com/article/2017 ... rman-court (magazine article.).
The relevant judegement: LG Hildesheim, 3 O 139/16
For German speakers/residents you will find a bunch of legal companies offering to put in a case for you are a fee. The lawyers looking for business seem to prefer a cash payout and take about 35% on a no foal no fee basis. If you have Rechtschutz then it might be better to go after a new car and use this cover to pay for the lawyer.
I don't know the German systems but in some countries if you lose in a blatant case like this you also have to pay the costs so the lawyers looking for a high percentage seem to me to be like US "ambulance chasers".