Jamie Corstorphine drives the new Mercedes-Benz C-Class coupé, for UK motoring magazine, Autocar. The model being reviewed is a diesel-burning 201bhp C250 CDI; capable of hitting a top speed of 149mph and 62 mph in 7.0 seconds, it’s not exactly a slouch, but it can also return 52.3 mpg – when driven sensibly, if that’s your bag…