Can anyone tell me what the gizmo is in the attached pic?  I’m guessing it’ a light sensor, but it’d be good to know for sure, as I’m thinking of placing a dash cam mount close to it. 

Pretty sure it's a vent or just plastic...

 

The rain/light sensor is the round thing above it.

The lane assist, traffic sign assist and high beam assist is the triangular cut-out.

The auto-dimming mirror sensors are on the actual mirror, one facing each way.

It is a blank piece of plastic. On certain models a camera for high beam assist is there, often called a low line front facing camera. But the round circle above it contains the light sensor and rain sensor. 
I have a high line camera, heated windscreen and it is much more prone to interference, as long as whatever dash cam you are fitting is a good quality one with a ferite core for the power lead, youll be just fine.

Thanks for the replies.  I'm looking at a Garmin MIni 2, as I'm not a fan of 'big' cameras with displays.  I'm not sure their hardwire kit includes a ferrite core.  If I add one, does it need to be at the camera end or the voltage reducer end?

9 minutes ago, GarySN said:

Thanks for the replies.  I'm looking at a Garmin MIni 2, as I'm not a fan of 'big' cameras with displays.  I'm not sure their hardwire kit includes a ferrite core.  If I add one, does it need to be at the camera end or the voltage reducer end?

as close to the camera end as possible, so mine is in the A pillar the wires run down. 

Cool.  Thanks.