Audi RS 6 Avant Review

If you could own exactly one car, this would be a serious answer. The 4.0 litre twin-turbo V8 makes 591 horsepower with mild hybrid assistance, the air suspension flattens a broken road and then firms up when asked, rear axle steering shrinks it, and behind the seats there is a proper estate boot that takes a dog and a week of luggage. It is discreet enough to park at a school and fast enough to embarrass a sports car on a wet motorway.

The problems are all financial. Fuel economy is genuinely poor and the tank empties quickly when you use the performance. It weighs well over two tonnes, so tyres and brakes wear at a rate you notice. Out of warranty, an air-sprung twin-turbo V8 with 48 volt active anti-roll is one of the more expensive things you can own, and the complexity is not theoretical. Depreciation is heavy, which is a gift to the second owner and a wound to the first.