BMW's flagship coupe, the M8, has yet to be revealed, but it has already been teased to kingdom come and leaked almost in full. The M8 will be powered by a 4.4-liter twin-turbo V8 producing over 600 horsepower, with the Competition version offering around 625 hp. This is a sizable bump in power over the M850i xDrive, which produces 523 hp from its twin-turbo V8. But if you've simply grown tired of seeing endless teasers for the new M8 and don't feel like going through the hassle of trading in your M850i, why not turn to AC Schnitzer?

AC Schnitzer is an aftermarket tuning company known for taking BMW models to the extreme, having recently tuned the M5 Competition to produce 700 hp. Now the German tuner is turning its sights on the 8 Series in both its 840d and M850i variants. AC Schnitzer upgrades, which include a warranty, bring the 840d from 320 hp to 380 hp while the M850i gets an even more sizable upgrade, going from 523 hp to 620 hp. This means AC Schnitzer's M850i will likely keep up with the upcoming M8, even in its Competition trim.

In addition to the engine upgrades, AC Schnitzer also includes a new exhaust system with sports rear silencers. The exhaust has two modes - sport and comfort - and sounds pretty beastly in the video shown above.

The car has also been upgraded visually with 20 mm lowering springs. There are also a ton of aerodynamic improvements including carbon fiber front spoiler elements, a front splitter, front side wings, hood vents, side skirts, a rear diffuser, and a rear spoiler to round it all out. To complete the look, buyers can choose between a lightweight set of forged wheels or alloy wheels. We could do without some of the tacked-on aero upgrades, but AC Schnitzer's engine upgrades seem worth the money.