I agree with what everyone says about a WDH. Personally, I would not tow without one. I just think that you are going to find that there is no way to use one with the current receiver design for the Touareg. Ray is right, too. All jacking up the rear shocks with air is going to do is raise the back up, but you'll still have the hitch loaded exactly the way it was before pumping up the rear shocks. The important thing about the WDH as he points out is that the load is shifted (and shared) by the front and rear axle of the TV as well as the trailer. Air shocks will make things level, but a WDH levels by distributing the load better. Jacking up the rear shocks with air does not increase the load felt on the front axle, therby increasing the ability to steer & control the trailer. But I do believe that when the engineers at VW determined that the Tourareg could safely tow 7700 lbs, those loads were considered because they knew the vehicle would only be weight carrying not weight distributing. Given the weight of the loaded TM, there ought to be plenty of margin. (You just won't be able to find anyone at VW that can confirm it).
Also, when you go to the dealer be sure that you get the OEM hitch. That's pricey (about $800) but right now it is the only one that is rated at Class III. There's an after market variety -- lots cheaper (about $150) but its only a Class II... and a Class II is only rated at 3500 lbs.
Additionally, you are suppossed to get a letter from VWOA telling you what the REAL tow ratings and capacities are. Ask your VW dealer about it.
I hope by next model year (2005) they'll have all this worked out with the Touareg. It's a great car from what I can see, and I'd buy one in a minute if I had any confidence that ANYONE at VW or VWOA knows the real skinny on the hitch, brake controller, etc. From what I can see, they just aren't there yet.
Finally, I'd recommend you go to
www.vwvortex.com and go to the forum on Touareg and search what owners say about towing, hitch, etc. Here is the link to take you right to the T-Regg forum:
http://forums.vwvortex.com/zeroforum?id=39. Everything I learned (gleaned) about this vehicle came from those forums -- but it was enough to convince me to hold off for another year.
EF