Where is this nut located? I don't see it in the pics on the DIY I pasted the link to up above.

I'm doing this in a couple of weeks and I'd rather have a spare metal one ready when I start.

 

The nut is between the filter and the gas tank. As soon as u can see the filter you'll see the bolt and nut.

 

i heard that you have to go to audi to change the tranny fluid? since it uses a vacuum system to take out the fluid and then they pressure shoot new fluid into the tranny? am i completely wrong or do i have to go visit audi? >_<

 

it's my understanding that any shop with the right equipment can do that, or even yourself if you have it. It doesn't have to be Audi, but should be a shop you definitely trust...