I bought my 2014 Passat in August 2019 and the Carfax report said the heater core had been replaced at 35k miles. I thought that was odd but didn't think much about it. Last February I lost all heat and promptly got the car into the dealer. They told me the heater core was plugged and it would be replaced under warranty. Unfortunately the mechanic didn't make sure the hoses were on right and the next day I had coolant dripping on my carpet. Back to the shop it went, the manager told me they had to replace the heater core again because they received a defective one and would clean my carpet as well. Six days later I get my car back, and I have heat through the rest of the winter and spring. I don't use my heater until last week and notice that the passengers side of the windshield is not defrosting. I turn the heater on high and feel the vents on that side, and the air was cold. Now I'm thinking that it's probably something wrong with the vents not working on the passengers side. I take the car to the dealer because it's still under warranty. The shop tells me heater core is plugging up again, but they have a new way of flushing the system that should fix the problem. It's only been seven months since the last heater care replacement. I have 20k miles left on my warranty and if I have to put one more heater core in this car I will be trading it in on a Toyota. This is reticuloses, and bad engineering.