Rear Tail Lights

Hi,
New to the forum plus also new to Audi.

I have just bought (2weeks ago) a new Audi A4 Avant 2.0 tdi. Really nice car infact best one I've had. I have one problem which will probably mean a trip back to the dealer, my drivers side rear tail lights have failed to work a few times but then amazingly correct themselves the next trip, I get an info message in dashboard stating this. Just wondering if this a known problem because as the tail light is split, one part is on the hatchback and the other is part of the chassis, both are not working.

Any ideas would be great.

thanks

Just back from dealer, the light unit which is meant to be sealed has condensation inside thus giving a connection problem. The light unit is being replaced tomorrow
Thanks