Do you remember the term 'Q-car', which referred to something that didn't look fast but actually went like the clappers?
It was popular in the 1950s and '60s and had its origins in the World War II, when the Royal Navy deployed vessels that looked innocent, but were stuffed with armaments and a lot quicker than they appeared. They were known as Q-ships.
The Audi RS6 estate is almost a modern Q-car, but its huge alloy wheels, low-profile tyres and bulked-up bodywork are giveaways that its primary purpose isn't to be filled with Ikea flat packs, although the car is perfectly capable of accommodating them.
With a 4.0 litre V8s engine mated to an eight-speed self-shifting transmission that can be manually controlled, it provides brute force without the ignorance, getting to 62mph in a motorcycle-like 3.9 seconds and thundering to a limited 155mph.
Really the car is a plaything for the super-rich, having Lamborghini-like performance but without the willy-waving vulgarity. If you can afford a car like this, then presumably you can afford 29.4mpg. And in that case, you could use it every day.
Although hardly nimble, the thing gets round corners with a combination of thuggishness and great precision, and will accelerate like an anvil dropped off a cliff, yet it will truckle along in traffic without complaint. The ride is rather better than you might expect.
The inside is inevitably dripping with kit, and to our eyes just crosses the line from tastefully modern into techno-bling, with little speakers that rise out of the top of the dashboard just one example of its aesthetic grandstanding.
Beautifully made, spectacularly fast, thoroughly practical (fold the seats and it would swallow a wardrobe) and utterly pointless, the Audi RS6 is both a very silly car and a serious piece of kit.
Practically daft, or daftly practical?