The Audi RS6 is the car that can swallow an entire family, plus the haul from a trip to Ikea, and then still fly to 60mph in barely four seconds. It might be the most capable on road car in the world. But it’s changed. Whereas the Audi RS6 used to be a subtle speed machine, the new RS6 looks as angry as its go suggests. Does that mean some of the spark from the old Audi RS6 has been lost? Or is it still just as good and just as capable as ever. Would you buy an RS6 or head over to Mercedes for a