What is it?
If you can pull the strings, there's good reason to debut a new two-tonne, five-metre, four-door performance coupé at a Grade 1 FIA-specification racetrack.
If the car can match the 0-62mph time of a McLaren F1 – as the Mercedes-AMG GT 63 S 4-door does – it probably won’t feel too lost on the endless stretches between corners. More temptingly for the manufacturer, such a perfectly surfaced expanse is the greatest hiding place on earth for big cars with poor manners out in the real world.
Mid-winter in Aberdeenshire could hardly be in greater contrast to the Circuit of the Americas, current home of the US Grand Prix and venue for the international press debut of AMG’s four-door take on the GT hot-rod coupé last year (you can read about it, with plenty of detail, here). It's therefore an excellent environment in which to see whether AMG's answer to the Porsche Panamera and challenger to the upcoming Audi RS7 is really worth the £120,000 asking price.
As a quick recap, the four-seat (or, optionally, five) interpretation of the hot-rod AMG GT Coupé comes in two flavours: the 577bhp GT 63 and a £15,000-dearer 630bhp GT 63 S tested here (look for the yellow brake calipers). Both use a version of the AMG's monster 4.0-litre M177 V8, though in the case of the S it is plied with unprecedented boost pressure from turbochargers with a revised turbine geometry and new low-friction ball bearings.
Both get a switchable performance exhaust, 20in alloys and a extending rear spoiler, though only the S gets the AMG Dynamic Plus pack, which includes active engine mounts and, this being 2019, a rear-drive-only drift mode.