Usually I'm home in time for Watchdog, but last night I missed the whole of the Ten O'Clock News. Why? Because I was driving the BMW 635d, that's why, and I promise you this - when you drive it, you too will take a monster detour.

You'll find yourself on unnecessarily selected back roads, carving the sublimely compliant Six chassis from apex to apex at a wholly indecent pace and actually gritting your teeth with pleasure at the way the steering reports the cambers and the rear tyres bite. And, like Dr Jekyll, you'll arrive home not quite knowing how it happened.

This is a diesel, for God's sake. An oil-burner, a smoker, a drinker of premium spirits at one-twelve a litre. I know this because it says so on the bootlid. It says there's a 3.0-litre twin-turbo with third-gen common-rail fuel injection on board. It says you've got 286bhp and 427lb ft of torque to shuffle.

But in the cockpit there's no derv DNA - it's pure sports car, leather-wrapped and sublime, a place of both work and pleasure, performance and function. Absolutely all balanced to perfection, a chemical reaction only achievable in lab conditions. Or in Munich.

Something genuinely big has happened here. The scandalously off-kilter idea of slotting an oil-burner under such a lengthy bonnet should not, in itself, be breaking news. But the execution is so flawless it takes your breath away.

Tonight I'll listen to the Ten O'Clock News on the radio. In the car.

Source: Top Gear