I've noticed that, when manoeuvring, my steering rack seems to groan slightly. It does it a bit a slower speeds too. Is this a common thing or should I get the dealership to investigate when it's in for its first service on Thursday?

Mine also does that but it seems to be due to the steering wheel ever so slightly touching the steering column. In my case it is in a 9 o'clock position and every time I do a low speed manoeuver the resulting friction creates a subtle noise. It does not interfere with the manouevrability of the car in any way. If it sits in the sun, the plastics dilate and it sound worse. During the winter season I hardly heard it. It seems to be just one of those annoying rattles, not safety related so minor, but I will mention it when I get it serviced.

My superb has been doing this for years. No problems. I have got used to it.

The tech sprayed some silicone spray onto the CV boot which hasn't made any difference. Unless it gets worse, I'll put up with it. 

I have the same issue on a Octi 3, but I've noticed that it only occurs when having the turning signals on and steering left or right while the signal is still on.

Mine has been in the garage for the suspension top mount replacing today - seems to have cured the problem. However now a new problem, the wheel alignment is slightly out!!