What I'm I missing here ??

[J.R.]

I want to put up my Audi TT rear Auto dimming mirror but my window screen mount seems to be different from my original A3 version "look @ pics below"

I'm I missing some part or something ?

Old original A3 mirror :

New TT rear mirror :

 

[fangio]

Hi, your mirror is a basic auto-dim, but the TT one is for the auto-lights/rain sensor set-up also.
Practically everyone advises a change of windscreen for the different mount, as it invariably breaks when you try to remove the old one. The new mount will incorporate the sensor.

http://www.audi-sport.net/vb/a3-s3-...xterior-mirror-whit-compass-not-done-yet.html