My goal basicly was to make my car even more quite to drive, than before.
I had already tried dynamat with little outcome, so I decided to try using a 3M Sound dampaner spray.

The spray leaves a plastic layer, and is sometimes used for undercoating. I got it at my local Murrys discount auto shop.

I started off by cleaning the wheel wells very very well. Got all the dirt off as possible.
Then one by one, I removed each wheel and put two layers of the spray around each well (careful not to spray the brakes, etc)

Then, I removed the front door pannels and put two layers of the spray around anywere I could. Mostly the plastic and sheet metal area. After letting it dry, I put the doors back on and took it for a test drive.

Results
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Audi makes quite cars to begin with, but I honestly can hear a huge difference after using the spray. Where before I could here the thumping of bumps, ruffly paved roads, and crunching of gravel roads, now I rarely hear more than the whisper of wind.

Of cource i can still hear some bumps, gravel, etc, but its much less often and much more quite. It took awhile to get used to feeling bumps but not hearing them.

While its just an illusion, it makes the car feel smoother to drive.
Not bad for $10 of equipment and an hour of work

If anyone would like me to post more detailed instructions or pictures, let me know.