Talked to a lawyer right after the initial announcement, whose company deals with this type of litigation (defense, they handled many oil spills) and we both agreed to my thought that they would have been better served both financially and PR
Buy back every one and/or offer a new, non-offending version...then either destroy them all....or sell/give them away to a country without smog regulations...bet him it would have cost less back then...he now owes me a Costco Dog lunch...
Win/win...but they fought and continued in their position...until outed...but we have what they have now...