The EQXX's exterior features various stylistic cues that help maximise its aerodynamic efficiency, and numerous eco-friendly materials that adorn the interior.

[5][6] The EQ concept went into production at the end of 2019, and like its later EQA and EQB siblings, it was constructed on a platform designed for internal combustion engines rather than a battery electric vehicle.

Mercedes-Benz Chief Operating Officer Markus Schäfer [de] also announced alongside the teaser the reveal date of the EQXX, which was to be 5 January 2022 at the Consumer Electronics Show.

[16][17] Initial design on the EQXX began in June 2020, after a request from the company board for an electric vehicle with 1,000 km (621 mi) of range.

[19][20] The EQXX's lithium-ion battery pack and drivetrain were largely developed in partnership with Mercedes AMG High Performance Powertrains.

Several changes were made to optimise the efficiency of the powertrain, starting off with redesigning the inverter, now incorporating Onsemi's silicon carbide anodes,[21] along with the engine control unit being almost identical to the one utilised in the Mercedes-AMG ONE.

Cell-to-pack creates tighter packaging because the cells themselves are not separated into modules, but instead are directly placed into the battery pack itself without any sort of physical partition.

[24] A sugar cane-carbon fibre composite forms the lid of the 'OneBox', a structure which compartmentalises the electrical components and is said to weigh 495 kg (1,091 lb).

[28] A single-speed direct-drive transmission transfers power from the battery pack to the radial flux motor located at the rear axle, which produces 150 kW (204 PS; 201 hp).

[29][30] A cooling plate situated below the car provides a passive method of heat transfer, with shutters that can be adjusted to control airflow.

[36] The interior features various eco-friendly materials; the carpet is woven from bamboo fibres, and the seats are adorned with faux leather made from mycelium.

The rear features Kammback styling and has an axle track 50 mm (2.0 in) narrower than the front, in order to create the ideal "teardrop" shape.

[41] The decision to retain wing mirrors was made on the basis that an electronic camera system would draw too much power and negatively affect the range of the car.