AdBlue tank rattle?

I have a 2012 Touareg TDI with 3,500 miles. I noticed a faint rattling type noise which sounds as if it is coming from the rear. It sounded like something loose near the trailer hitch or perhaps the exhaust. The noise is not speed dependent. I think it is a little worse after the car is warm. I dropped by the dealer today and had the service tech ride with me in the parking lot. We just drove a small loop around the parking lot at 5 or 10 MPH. We both could hear the noise. He told me this was normal and that it was just the AdBlue tank. It does not make the sound like a liquid sloshing around. He said the tank isn't loose, but that it is just a noise it makes and that it is normal. I checked in the rear and made sure the spare was tightened down and that nothing was loose. I couldn't find anything. Does this AdBlue tank story sound right? I'm thinking not. Thanks in advance.

Have the dealer tech drive you around in another 2012 TDI blutec similarly equipped to yours. If you don't hear the noise, he is wrong.

x2. I've only been a Touareg owner since last May. But I'm not buying that guys malarky either. Presumably you've check under the deck lid for the noise. So I'm wondering if you have your ball mount installed in the hitch receiver? Mine had a very annoying rattle until I shimmed it.

//greg//

I have not heard this noise you speak of in my '12 with similar mileage.

X-2 on that comment, No noise in my 2012 TDI . The guy probably never drove in one before. JP