Plot: As Jaguar prepares to launch its new Sovereign in the United States, William Woollard compares it to its deadly rivals from Mercedes and BMW. At the cheaper end of the market, a look at the range of mopeds available — how well do they perform and how safe are they? Chris Goffey asks whether car manufacturers can learn from the sophisticated electronics fitted to the latest tractors, and Frank Page investigates some deals and discounts available when you try to buy a new car