What is it?
Audi's rival to the BMW M6 GC and Merc's CLS63 AMG, and faster than both. Faster than pretty much everything. The RS7 has the same stellar 4.0-litre, 552bhp turbo V8 as the RS6 Avant, but housed within the A7's swoopier five-door-coupe body. Four-wheel drive, naturally, comes as standard.
I'm guessing it's not slow?
You guess correctly. In a revelation as unsurprising as it is welcome, the RS7 shares the RS6's ballistic turn of pace, carving great chunks out of the horizon with every injudicious stab of the throttle. Officially it'll do 0-62mph in 3.9 seconds and, with the right option boxes ticked, 189mph. After a day's spirited driving on good German roads, we have no reason to doubt these numbers.
That's the thing. It isn't. There aren't many 550bhp cars you can take liberties with, but the RS7 feels virtually idiot-proof. Jam the brakes mid-corner, barrel into a hairpin 50mph quicker than you meant to, whatever: the big Audi smothers all your stupidity under a great picnic-blanket of electronic cleverness and relentless grip. It's a freakishly effective machine for getting down just about any road at near-unimaginable pace, instantly transforming you into a far better driver than you really are.
So what's the drawback?
As with all hot Audis, the RS7 isn't the last word in feelsome handling. In fact, it's barely in the second half of the dictionary. The steering's hazy, and trying to ascertain what's going on with the tyres is like playing piano in oven gloves. It's a big, heavy bus this, and one that, like the RS6, leaves you feeling rather as if you're experiencing a very good video-game version of reality rather than reality itself. That said, it's more fluent and engaging than the oddly lumpy RS4. And it sounds like...
...let me guess. Thunderstorms, bellowing giants, industrial machinery?
Yes. You have spent too much time on TopGear.com. And only if you spec the sports exhaust. Which you shall.
Any other must-tick boxes, Dr Options-List?
Well, UK-spec cars don't get the sportier steel-spring suspension nor carbon-ceramic brakes as standard. The latter - though a pricey option - are a must, the RS7's standard stoppers feeling a touch overworked when hauling its near-two-tonne bulk to a standstill. The standard adaptive air suspension, however, should be a better fit for British roads than the pricier steel set-up, which is too harsh in even 'comfort' mode.
So, this or that lovely CLS?
Good question. A couple of months back we compared the RS6 Avant to the Merc E63 AMG. The same conclusions would hold for the RS7 against the CLS63: the rear-drive Merc offers more drama and involvement, but for devastating, accessible pace, the all-wheel drive Audi is king. Same deal were you to face the RS7 up to the similarly powerful, rampantly rear-drive BMW M6 Gran Coupe, which, it's worth remembering, starts some £14,000 dearer than the Audi. The Beemer's more interactive, the Audi's more flattering.
I want to be flattered by my German luxo-barge, please. Shall I place my order for an RS7?
If it's Audi and it's fast, we'd take the RS6 Avant every time. Not only for its capacity to transport an extended family of Weimaraners, but because somehow the estate makes better light of the big RSs' inevitable dynamic limitations. In the Avant you think, 'Sure, it's heavy and a mite distant and it leans a bit, but hey, it's an estate!', while the RS7 isn't quite hands-on enough to justify its sportier profile. Plus a hypercar-crushing estate is just that little bit cooler than a hypercar-crushing five-door-hatch-coupe-saloon...