 I bought my second Passat on 2013 - a TDI Diesel for the mileage since I have a long work commute. The cost of my checkup last year by the dealer was ~$600 since they are the only ones that can add the blue liquid stuff.  I just had to take it in 12 months post the expensive checkup because the blue tank heater stopped working and this cost ~$1400.  Outrageous.  And everyone I talk to that owns or has owned a TDI had to replace the same part.  Defective part coupled with bad engineering. I will not be buying another VW product.