I believe dual carriage ways are 60mph unless there is a central reservation in which case they are 70mph.
On the matter of reviewing the Fox for me as a relatively new driver I believe that the fox is a good car to get to grips with. Although my model is the 1.2 petrol with 54 bhp (I believe) it still does have a nippy feel to it when going at the 60 mark on country roads. Nobody said that the fox was going to be great for acceleration and the likes but it is as advertised; a cheap car to buy, tax, and insure. You get what you pay for at the end of the day and for me the fox is more than ideal for my journeys.