With output figures of 550 horsepower and 600Nm of torque, the V8 under the Aston Martin DBX’s bonnet already has an abundance of oomph. But the boffins in Gaydon don’t seem to have been content with that. That’s why they have now announced the new DBX 707, a significantly higher-performance version of the Aston Martin DBX, boasting a host of mechanical upgrades that make it the most powerful luxury SUV from a mainstream automaker.