I don't believe this is isolated to Skoda or VAG... Our Volvo has the exact same problem / feature

Every now and then under special circumstances it delivers some faulty warnings. 

I regularly use a stretch of road where I leave a large roundabout and join a dual carriageway via a sweeping left hand turn. If I resume my ACC too early the car brakes sharply. I assume this is because the radar is picking up the metal crash barrier in the central reservation.

20 hours ago, BriskodaJeff said:

Not had this one, but I did get one the manual warns you about last night. Right filter lane at a left hand bend. Looked almost exactly the same as fig A. I've driven the road loads of times but I don't think there was ever a car turning right in the filter before. Dash lit up red, but it didn't get a chance to brake as I recognised what was going on and blipped the throttle. As soon as I was past the filter it was normal operation.

@Speedman is it possible you were on a bend so the radar was pointing off-centre toward one of the vehicles in the next lane, rather than at the car in front?

Hi, No this was  was a perfectly straight piece of 3 lane motorway - I have looked back at this on my dashcam and the car in front is a reasonable distance away and neither this or the cars either side slow at all. The only thing I did notice is that the car in front and the ones to both sides are all doing exactly the same speed - wonder of this could somehow have confused it. I use ACC regularly and this is the first time it happened so assuming it is not a common issue.

26 minutes ago, Speedman said:

Hi, No this was  was a perfectly straight piece of 3 lane motorway - I have looked back at this on my dashcam and the car in front is a reasonable distance away and neither this or the cars either side slow at all. The only thing I did notice is that the car in front and the ones to both sides are all doing exactly the same speed - wonder of this could somehow have confused it. I use ACC regularly and this is the first time it happened so assuming it is not a common issue.

Odd. Not one I've come across (yet).