Lee23404:47.5 mpg in a family sized, petrol, automatic car seems pretty good to me. I wouldn't complain too loudly,
I think that the point he was making is that the previous, less economical model, gets better than 47.5MPG in every day use, so he was querying what Autocar's test conditions were. Presumably they did a fair bit of 0-60 style testing?
FWIW, our MK2 Prius has the automatic parking and I hope it's been significantly improved in the MK3. In ours, it's a bit fussy to get working - you have to make sure you've lined the wheels up straight ahead, press "ok" on a legal disclaimer, select whether you're parallel parking or car park parking, confirm that the camera has worked out where the parking space is correctly, then release the brake enough to let it do it's think, but not go too fast otherwise it cancels the function entirely.
When it works it is very impressive. But if it spots the space incorrectly and you have to shift it using the on screen buttons, it takes so long that you'd need to be seriously incompetent at parking to use it regularly.
That said, something that the reviews never seem to bother to tell you is that the reversing camera you get with the auto-parking function is extremely good. It overlays the view behind with lines that indicate where the car will end up given the amount of steering lock you have on, which makes it very easy to sidle into tight parking spaces. The reversing bleepers on my BMW mean you can't really get closer to obstacles than one or two feet - the camera on the Prius lets us get to within one or two centimetres of an obstacle.