Since I've bought the car, I've been getting an intermittent groaning sound when I am reversing. It only ever happens when the steering isn't centred, and seems to be worse when full lock is applied. Any clues?

I was going to ask if this was because you were engaging reverse whilst still doing 5mph forwards? But then I remembered only company car Vectra drivers do that.

Power steering pump, or belt slipping.

Mine did it this morning strangely enough, its happened occasionally on every car i've had with PAS.

Power steering pump, or belt slipping.

Power steering pump I reckon - you can probably hear it if you are stationary and hold the wheel on full lock.

I have experienced this type of noise too with cars with PAS. It is normally audible at low speed with lots of steering lock applied. I don't think I would be too concerned if my Octavia made the noise in those circumastances.