I've got 90,000KM's on my 2015, never had any issues other than an Adblue line replaced.
1. People come here with problems, those cars that don't have problems don't show up here.
2. On this car and my 2013 with 150,000, never had a heater core issue and heater worked/works fine.
3. The 2013 had a CEL for the DEF Heater early on before dieselgate. Dealer/VW said not covered on emissions warranty, car had about 85,000 KM's, so off original warranty. I argued if DEF isn't part of emissions, remove it. In the end, it was fixed under warranty.
4. Oilhammer, when I am off warranty, I would get mine "fixed" if you were handy.
Warranty by manufacturers is hit or miss, some are better than others, some are very bad. The worst car I ever owned was a Toyota Camry and Toyota did not stand behind it. Mercedes cars are now rated very low on the quality scale. Toyota have been fixing frames of their Tacoma, Tundra, and 4 Runners from say 1996 on, they are now doing 2010's. They are doing that in my opinion due to the liability issues- lawyers made them do it after frames broke in half while driving down the road. Not sure why they haven't fixed the frame issue.
The alternatives today for new cars are scary to me. Everything said about dealer tech talent being lacking in many or most cases is accurate. It is Russian roulette getting a good tech and new cars are getting much more complicated. Manufacturers and dealers first process is to check your wallet and you have to fight them to get what is fair and reasonable.
If you buy a new car, it has radar, 360 degree video, automatic cruise, automatic braking, engines turn off when you stop at a light then restart, hybrid gas/electric, a video touch screen that runs the audio, heat, navigation, etc. and many must have 2-300 sensors for all those gizmos. Each car in a model year can have different hardware let alone software. If you have any issues- and I can't see these things working perfectly forever- who will fix them?
I've seen videos on Tesla videos showing the inside of a battery pack and other technology inside them. They are very scary too and Tesla does not have a good reputation for service or quality. I thought an electric car would be in my future, now I ain't so sure. Getting rid of internal combustion was supposed to remove a lot of systems.
We'll likely have a call center the car will connect to over the internet, you'll sit by the side of the road on hold, then the call center will plug into your car, do a bunch of attempted fixes over an hour or so, then send an Amazon tow truck to tow you to who knows where to replace something?
Oilhammer, I hope your training is up to date, you may be our only hope.
I'm now retired, at this point I may not buy any car newer than a 2015, I may revert back to a 1998 TDI.