There are slightly differences of the car camera for each Audi which you may not be able to distinguish it easily. Here you go few tips :-
In general, there are three car camera models namely Audi, Audi 2016 and Old Audi models, both basically fit for most of the Audi car series.
↑Audi 2016 ↑
(1) How to distinguish New Audi and Old Audi by Rearview Mirror Outer Case and its’mounting:
↑Characteristics of New Audi ↑
↑Characteristics of Old Audi ↑
(2) How to tell it is Audi 2016?
Though Audi and Audi 2016 possess the same Rearview Mirror Outer Case, you can simply distinguish by the shape of buckles at circled as shown below :
Firstly, according to the characteristics of Rearview Mirror Outer Case, you must now clear that your Audi is New or Old model. Then you can easily distinguish between Audi and Audi 2016 by shape of its buckle in interior part of plastic case.
P.S. You can even install your original built-in “Temperature / Humidity Sensor” in Old Audi as below:
To make your job even easier, you could simply tell us year of your model, interior color preferable with images of rear view mirror, then we will pick the right one for you.