Building the World’s First ONYX Mercedes G-Class 6×6 Part 1
At Kubay Design, we’re building what will become the world’s first ONYX-style Mercedes G-Class 6×6 — a project that pushes our engineering, our craftsmanship, and our carbon fiber expertise further than ever before. The client arrived with a 2016 Mercedes G-Class already fully converted into a striking ONYX body kit. Our task: transform this exact vehicle into a full 6×6 conversion while preserving the unmistakable ONYX design language that makes it so recognizable.
A Truly One-of-a-Kind Build
This project stands apart from anything we’ve built before. Since most of the existing ONYX body panels were manufactured from fiberglass, our first step was a complete teardown of every exterior component to properly assess the true condition of the chassis underneath. With the vehicle nearing 10 years of age, imported from the UK as a right-hand-drive model, years of exposure to high humidity beneath the body kit had left considerable corrosion on the body. Our team is now fully restoring every affected area, repainting the vehicle, and simultaneously re-engineering each body panel to integrate with the new 6×6 platform.
Re-Engineering the Wheel Arches for a Wider Stance
One of the most demanding parts of this build is the complete redesign of the wheel arch extensions. A genuine 6×6 conversion requires portal axle gearboxes and 37-inch off-road tires, which dramatically widen the vehicle beyond what the standard ONYX arches were ever designed to cover.
Front Arches: Reshaped, Yet Faithful to ONYX
The front wheel arch extensions are being reworked and re-modeled from scratch, engineered to remain visually true to the original ONYX aesthetic while accommodating the new width. Custom carbon fiber overlays are being designed specifically for this purpose, keeping the signature ONYX silhouette intact.
Rear Arches: A Complete Structural Transformation
The rear arches demand even more extensive work. Our team is cutting into the existing arch structure entirely and re-modeling its shape to match the completely different geometry created by the 6×6 rear-end conversion. Each rear arch will also gain roughly 10 centimeters of carbon fiber widening — not just for correct proportions and a seamless fit with the rear bumper, but to ensure the wheels sit fully enclosed within the arches, meeting European regulatory requirements.
A Fully Functional 6×6 Drivetrain
This isn’t a cosmetic third axle — the technical side of the build is just as thorough as the bodywork. A through-axle drive system will be installed, giving the vehicle genuine, permanently functional 6×6 four-wheel-drive engineering across all six wheels. The factory transfer case, low-range gearing, and all original four-wheel-drive modes are being preserved and fully adapted to the new three-axle configuration.
A Complete Interior Transformation: G-Class 2025 Inspired
Perhaps the most striking part of this project is happening inside the cabin. The 2016 interior is being fully transformed into the styling and comfort standard of the new-generation Mercedes-Benz G-Class W465 (2025). The steering wheel, dashboard, front seats, and a wide range of interior elements will all be replaced — with the front seats gaining massage, ventilation, and heating functions.
Rear Cabin: A True Limousine Experience
We’re also completely reworking the rear cabin. One of the G-Class’s well-known limitations is limited rear legroom, so we’re installing a rear bench seat on custom sliding rails, allowing it to slide backward and create dramatically more legroom — effectively delivering a limousine-like experience. The rear seatback will also recline and adjust, with dedicated ventilation, heating, and additional airflow for rear passengers. The headliner is being fully rebuilt as well, featuring a custom starlight ceiling effect.
A Signature Color Story: Interior Meets Exterior
The interior’s primary color will be a vibrant lime green, an accent we’re carrying through to the exterior as well — the wheel rim lips will be finished in the same lime green tone, tying the entire build into one cohesive, unmistakable identity.
More Than a Third Axle
The result won’t simply be a G-Class with an added third axle — it will be a completely reimagined vehicle: a genuine 6×6 build with portal axle gearboxes, 37-inch wheels, an individually re-engineered ONYX body, and a modern interior inspired by the 2025 G-Class. Most importantly, it will be the world’s first ONYX 6×6 ever built.
Follow along for more updates on this build, or get in touch with our team to discuss your own bespoke 6×6 or carbon fiber project.
