...If a WD system isn't allowed per the manual, then why does the sticker on the factory installed hitch show a tongue weight rating with a WD system?
I’m not sure which model year is directly being discussed.... but when I was shopping for a hitch to add to my ‘13 I found that VW/Audi/Porsche each have their own part number for the Touareg/Q7Cayenne (all appear identical). I almost bought a hitch from a ‘11 Touareg which would have bolted up. I ended up ordering the correct ‘13 specific part number. When I compare pictures of the ‘11 and my ‘13 they appear physically identical except the decals.
The ‘11 and ‘12 decal have weight distributing hitch placards where tongue weight and max tow for both Wd and non WD appear. The ‘13 hitch makes no mention of WD, yet the hitch and bolts appear to remain the same.
As someone else posted, I doubt they went through the hassle and cost to make a design change and all the paperwork required to cheapen up the hitch mount. In reality they probably kept making the same chassis and simply changed the placard to reduce liability and risk exposure.
...just like I don't think the Touareg is either, they are all sheet metal unibody designs. VW even made a Touareg specific stubby ball mount to reduce the torque applied to the hitch. I don't think your theory holds water.
Why is a sheet metal unibody a bad thing? It’s just engineering.
If I were betting, I’d bet that VW engineers over designed the hitch and receivers (like they do everything else). Why does a 10,000 lb hitch off a GM 2500HD weigh the same or less than the hitch on my ‘13?
As to weight distributing hitch placarding. It costs VW almost nothing to downgrade the tow rating, and at the same time reduce their liability exposure by a lot. Heck some companies don’t even offer hitches and the owner has an aftermarket installed and assumes the liability.
Also if you are going to sell a $250 hitch for $1200 (or more), it better look the part and appear to be top quality...