I have a Q2 but with the tech pack etc so will be the same as yours. Carista is great, loads of things you can change. To to their website and put in A3 as the car because the Carista website doesn't show many changes for the Q2, but since it's based on the A3 then most things listed there are changeable.
You should buy the dongle from amazon as you get a free month. Change everything you need to change and then see if it's for you or not. Don't buy a cheap dongle and then get the app because you don't get the free month then.
Thread here covering the A3 which applies to the Q2 too: