Hi there have you resolved your power issue?
I have just had a 1.5tfsi Q3 and had this issue. I can almost describe the initial few moments as a kangaroo motion.
It is a known fault with all 1.5 petrol engines in audi, VW etc and there is a software patch that has just come out. It's not mechanical its your ECU.
Google Audi kangaroo issue and you will see how a massive issue it is and they are not recalling car, simply sorting out those that complain. Patch came out Fri and I had mine done and it's like a new car.
