If you are one of those unfortunate individuals for whom even a 415kW BMW M5 just doesn't pack enough of an adrenalin punch, take heart. Kelleners Sport has just the thing for you.
This deceptively understated grey lady is the Kelleners Sport KS5-S, a tuned, tweaked and twisted re-incarnation of the F10.
Kelleners won't say what they've done to the engine, which leads us to suspect that some of it might not be 100 percent street-legal under Germany's draconian TUV roadworthy regulations.
Or maybe it's just trade secrets.
Either way, Kellener claims to have boosted the power output of the 4.4-litre, twin-turbo V8 from 415kW to 480 and torque from 680Nm to 790. Included in the upgrade is the removal of the electronic limiter, allowing the KS5-S to reach a quoted 330km/h.
Sports suspension, adjustable for ride height, compression and rebound damping as on a sports motorcycle and, and 20” rims in your choice of graphite silver, polished platinum silver or matte black complete the mechanical work.
The interior is also all grey.
But it gets a bit of glamour in the form of quilted leather trim with contrasting stitching, as well as a carbon-fibre trim elements, a special sports steering wheel and alloy pedals.
A complete carbon-fibre aero kit, including a front lip spoiler, new side skirts and rear diffuser insert, a boot-lid spoiler and side-mirror housings, sheds a little weight and make the KS5-S significantly more slippery - and more stable at speed - than the stock furniture.