There was a survey that went out to VW owners a while ago trying to gauge interest on different deals. The options presented were, in exchange for surrendering your car at a dealership, you'd get:

a) value of the car in Sept 2015 + 20%

b) value of the car in Sept 2015 + 30%

c) a replacement of your car - same model, same specs, same features, same color, but the 2016 model. Lease/loan payments would stay the same and you'd basically just get a newer replacement.

They specifically noted that the value would be determined by using a reputable car value estimation reference, so it won't just be some random lookup table that they've pulled out of thin air. Unfortunately, I don't see an easy way to look up historical values from KBB (haven't checked NADA), so I really don't know what the value of my Jetta was in Sept.

None of those things were officially from VW, but the survey was supposed to be somewhat confidential, so I can only imagine that the survey was contracted by VW.

Again: THIS IS UNOFFICIAL INFORMATION AND SHOULD NOT BE RELIED ON.