See that V10 badge on the trunk lid? It’s there for a good reason. This BMW Z4 got a heart transplant from Manhart as the tuners crammed in an S85 V10 engine from an M5. They did more than that as the aftermarket specialists bored out the powerhouse from 5.0 to 5.8 liters to unlock a massive 621 horsepower. You can check out the video to hear it sign its tune.

The hardcore roadster looks like a real hoot, although sending that much power to the rear axle requires an experienced driver that can tame the engine borrowed from a much bigger car. As a reminder, the V10 has its origins in the exciting world of Formula 1, back from an era when BMW was still involved in the crown jewel of motorsports.