Autenzell, Bavaria - Jochen Grommisch's G-Power workshop is more than just a tuning haus, often building one-off show cars and short 'boutique' runs of limited-edition specials order for major manufacturers.
But the backbone of the company remains making fast cars (especially those made in nearby Munich and wearing the Blue Propeller Badge) go much faster - and look even faster.
The G-Power signature is its all-black finish, as seen on this properly attitudinous customised BMW M4 coupé - but the real black magic is under the bonnet.
Grommisch's gnomes have tweaked the M4's classic straight-six turbopetrol by installing a G-Power Bi-Tronik 5 V1 piggyback microprocessor upstream of the standard ECU to provide modified mapping and a moderate increase in boost pressure, increasing outputs from the standard 317kW/550Nm to 382kW and 700Nm.
325KM/H FLAT OUT
That'll take the G-Power M4 from 0-100 in less than four seconds, to 200km/h in less than 12 and on to 325km/h flat out.
The plug-in unit retains all BMW's diagnostic and engine protection features, as well as two of its own; it won't give you the extra power until the prescribed coolant temperature is reached - and it'll default to factory settings if the oil temperature goes above a certain level.
The G-Power M4 runs the company's GM4-RS height and damping-adjustable coils and shocks, inside ultra-lightweight 20" Hurricane RR forged-alloy rims shod with low-profile Michelins.
And of course, all of these upgrades are available for the new M3 as well.