So when I am stopped at a stop light or sign or come to full stop, I hear this puff noise(not everytime)from the back exhaust (I think it's coming from exhaust)...sounds like a back fire in a subtle way.

 

This will be a lot of "ands". lol When I might have my music going on and the car is not on and Im not in the car and the bass bumps I can hear a rattling noise from my exhaust. Mostly the right muffler. Its not too loud, you have to be standing behind the car to hear it. Anyone else have a similar problem? Weird

 

It sounds like a misfire, perhaps a coil pack is starting to fail or is lose. I believe that there is a TSB on the coil packs.

Did the wet sanding take the scratches out of the paint? Post pictures of the finished product. Were you able to get Audi to replace the worn leather under warranty?

If I were you I wouldbe getting ready to drive the car through the dealer's showroom window. If I recall you have only had the car about 8 weeks and not only are you having the current issue, but you have had several other issues including: knocking noises from the brakes/suspension,
excessive engine noise while running, "jet engine" noisefor several minutes after shutdown, wheel shudder, MMI (screen and bluetooth connectivity). I guess the good news is thatit is all covered under warranty and that you get to road test the Audi loaner fleet.

 

After spending lot of time with them (shop foreman) brake and knocking noise is gone. Steering is fixed under warranty too. Scratches came out with wet sanding...I did post pictures.

Misfire sounds like this..hmm..I can have them look at it but for now its no big deal so I am going to enjoy the car for few more months since I have lot of time left under my warranty.

 

https://www.audiforums.com/m_857817/tm.htm

 

Great pictures. I am glad to hear that you were able to deal with the last 8 weeks.I would have probably gone nuts, but I am a little crazy when it comes to the car needing to be perfect.

 

I am so glad that the car is under warranty and Audi service was finally able to figure out without any fuss.

Still couple more small things that are not bothering me that much.