Radhamesheredia

I have a 2012 Audi ttrs my issue with it, is a "fume" "exhaust" smell inside cabin. It seems to happen when I accelerate "hard" like when I'm passing another vehicle, or even if I'm just running on a stable speed....it does not happen all the time but it does often. If you are going through the same situation or know what could be causing it.....please tell me. Oh and by the way, I have already taken it to an Audi service shop....and according to them,everything looks ok