Inside, there’s carbonfibre-reinforced plastic trim on the door inserts and centre console, a forged aluminium gear selector, a flat-bottomed wheel and bucket seats. AMG also replaces the rear bench with two trimmed wells.
The power brokers at AMG are clearly a hard lot to please. Power is up from the 478bhp of the standard CLK63 AMG to 507bhp at 6800rpm, endowing it with a power-to-weight ratio of just over 300bhp per tonne. Torque remains the same with 464lb ft at a high 5250rpm.
The engine is noticeably more responsive due to the adoption of a larger inlet manifold, reworked exhaust system and remapped electronics. It sounds great, too, a subdued rumble gradually building into a deep roar before erupting into an all-guns-blazing blare.
Power is channelled through Merc’s seven-speed auto, fettled by AMG for faster changes. Under light loads it swaps up smoothly, but bury the throttle and it bangs through the cogs with amazing precision. It’s no substitute for a proper manual, but you can call up gears at will via wheel-mounted paddles. Corralling it all is a limited-slip differential, which gets its own oil cooler and pump to keep temperatures in check.
Mercedes claims the 0-62mph time has dropped by 0.3sec to just 4.3sec. But remember, Merc is notoriously conservative when it comes to quoting acceleration. Top speed is limited to 186mph. “It is capable of more,” says Moers, “but the tyres are not.”
But it’s the handling that really steals the show. As those wheelarches suggest, there have been major revisions underneath, with the front track widened by 75mm and the rear track by 66mm. The Black Series also gets adjustable springs and shock absorbers that allow you to set your own compression and rebound rates.
On the road, the stiffer springs immediately make their presence felt. However, there is enough travel to ensure you’re not banged about too badly on pock-marked bitumen.
The new coupé also proves remarkably agile, the steering gives great feedback, and prodigious grip allows you to carry big speeds into corners and then plant the throttle early on the exit. Meanwhile, the array of driver aids, including a specially calibrated ESP, are nowhere near as intrusive as in the standard CLK63 AMG, so lurid powerslides are part of its repertoire.
Should I buy one?
Yes, if you really want the supreme performance Mercedes. It should be pretty rare, too. The bad news is that at close to £100,000 the CLK Black Series will cost as much as the new BMW M3 and Audi RS4. Combined.