Not sure if its been mentioned on here but people need to remember that only certain models have the remote smartphone access enabled system lets you lock / unlock the doors etc.
For example if you have a TT you are out of luck there is no "complete" remote smartphone App available and the 10 digit code is of no use to you, it cannot be entered into the MMI because the "Key user" prompt doesnt exist in the menu you can only be a "User".
Nor do you need the 10 digit code to be set as the "owner" by an Audi dealer, they can do this with just ID you take along to the dealership with your MyAudi app on your phone, and you do not need to be set as "owner" to use the basic level of audi connect anyway.
Dont waste your money on a code you cannot use if you have bought a used car and dont have the original 10 digit key code.
To get the basic audi connect system minus the remote access you only need to sign up to MyAudi , stick a SIM card with data on it into the SIM card slot in your glovebox and you will have a basic level of audi connect with google earth Nav , news, travel and fuel price info etc.
Lifted this from the Audi connect page.
"The feature "Audi connect safety & service incl. remote" is only available for the following vehicles:Audi A4 / S4 / RS 4, Audi A5 / S5 / RS 5, Audi Q5 / SQ5, Audi Q7 / SQ7 TDI / Q7 e-tron quattro. An overview of all Audi models with Audi connect and of all the services per model is available at Audi connect".