Effect of emissions scandal on Volkswagen resale value?

It's impossible to be definitive, but there's every chance that the VW brand as a whole will be tarnished over this affair and resale values of all models, diesel or not, could slump significantly. The size of the loss will largely depend on what the company does to salvage the situation and restore consumer confidence. If I were buying a VW now I would use it as an opportunity to squeeze a better deal out of the dealer. Your dealer has already dropped the asking price, but I would go harder on the basis that the resale value will suffer.