For people looking at a Touareg TDI, my experience with a 2016 is mixed. I am now at 102,000 miles. The car has never left me stranded. It used to start after sitting all day at -45 deg F. This past winter, it started after sitting at the Fairbanks airport for a week where the high temperature was -20F for the entire week, but it struggled. I suspect this was partially due to it still running its original battery. All of this is based on the car not being plugged in, as there apparently is no means for doing this on a 3.0 TDI
Problem areas: The adaptive cruise control is a nightmare. From Touareg-specific forums, I am not the only one. The problem is sporadic, so the dealer is never able to diagnose. The camera is $2,200 and the sensors are $1,800 each (there are two). VW has replaced the camera under goodwill, but it really never solved the problem which I've had since the car was new. Swap the windshield, and the cameras have to be realigned at $500. You can purchase your own alignment board, but the last time I checked, it was $8,000. FYI, I have not had any cruise control for the past 18+ months because I have not had the time to align my sensors after a snowy owl committed suicide by striking one of my sensors. The last Chrysler 300C that I rented incidentally had two cruise control modes, one was adaptive and the other was not. On a VW, if the car is not happy without the sensors, you do not have cruise control.
I do not have any sunroof leaks (nor do I have any leaks on my 2004 JSW). I know this is a VW issue and maybe it's because I've used the sunroof maybe twice since purchasing the car (same with the JSW), but my particular example does not have the issues that other VWs seem to have.
I am concerned a bit about the engine. My TDI extended emssions warranty will expire in 15,000 miles (it is shorter than the one negotiated for the Golf/Passat), so I sent my oil in for analysis at the last change. They don't really have a universal average for 3.0 TDIs but against whatever baseline they have, the metals were 3x their baseline average. These engines are known to have timing chain issues and God knows I've had my share with VW timing-chain equipped engines. I'm dropping from a 10,000 mile interval to a 10,000 km interval going forward. I'm not sure how much of my metal contamination issue is due to our climate; where I live, we never got above freezing (0 deg C) for 6 months. This equates to a lot of extreme cold starts. I'll see how the next analysis comes out. If I have to do timing chains, it comes off the back side of the engine, so transmission removal.
My engine uses coolant, probably 0.25L every oil change. It is a well-known leak from some EGR component buried deep in the valley of the block. I don't have the patience to have my dealer try to tell me that they can't find it (good luck telling your dealer that you know where it is coming from), so I will likely tackle this myself when the leak gets worse. It appears to be close to a 16 hour job for a $30 seal (more like $600 when you replace gaskets and seals to access it).
In the past few months, my keyless start has stopped working. From my VCDS scans, it appears to be failure of a convenience module. It is a $600 part if you could just buy it and slap one in. Unfortunately, it requires papal dispensation from the motherland, since it is linked to the vehicle immobilizer. Buy the $600 module from the dealer, and it is a $1,000 part. Of course the dealer has to troubleshoot the issue themselves, so add $400. Then add labor to install and program, and I am expecting my $600 part to cost me $3500 out the door.
I bought this thing because I was waiting for a 2016 Golf Sportwagen with the upgraded infotainment, but those cars obviously never showed up. With rumors of the 3.0 TDI disappearing, I literally bought mine on the last day before a stop-sale. The AWD is well sorted, the 26.4 gallon fuel tank is basically unheard of today outside of full size pickup trucks, and the car is very solid. On the other hand, I don't think Volkswagen has ever understood how electricity (or timing chain guides) works, and my Touareg has done nothing to dispel my suspicions. If the engine does not grenade, I will likely dump it at the 200,000 - 250,000 mile range assuming the component failure stays constant.
Another cost to consider: tires and brakes. I'll be limping my 4th set of tires into the winter (I've purchased two sets of winter tires, plus one additional set of summer tires for 25,000 miles/set but I probably have at least one more season on my winter tires before they are worn...so maybe 30,000 miles on a set of tires). A lot of people consume brake pads and rotors on these cars as well; personally I am still on my original brakes/rotors. Your driving environment may be different.