The best-selling model by far in the BMW 5-Series range, it represents around eight of every 10 leaving showrooms, which is no small number when you consider that the previous generation car sold a hefty 2.2 million during its seven-year shelf life. The 2.0-litre turbo-diesel engine produces 190bhp which is enough to get the 520d from 0 to 60mph in 7.5 seconds and on to a 146mph top speed. Those are very impressive figures, especially when you consider that it will also return 68.8mpg and 108g/km emissions. But beyond those figures the 520d's real story comes when you press the start button and set off. Yes it's a diesel and yes this is a mid-sized executive saloon but you can't help but be immediately struck by just how good this BMW is, even within the first 50 yards.