Remember the Lexus LF-FC concept? It was Lexus’s headline act for the 2015 Tokyo Motor Show, another pointy-ended, big-mouthed design study this time hinting at the look of the next Mercedes S-Class-fighting LS limo.

Inside and out, we were rather taken with how it looked, but it appears Lexus has been beavering away in the interim with the bits beneath all the edges and chickenwire. Because it’s just announced the LF-FC really will spawn a fuel cell-powered, flagship saloon car by the year 2020.

Now, the news that Lexus is dabbling with hydrogen isn’t totally shocking. Parent brand Toyota has already unleashed a road-going hydrogen family car in the shape of the Mirai, and the LF-FC concept hides a fuel cell drivetrain. The electricity harvested from the on-board hydrogen power station is sent to the rear wheels via a single e-motor, plus the front wheels by way of smaller individual motors housed within the front wheels themselves.

This set-up opens up exciting possibilities for torque vectoring handling wizardry (as per the Mercedes SLS Electric Drive) and rock-solid high-speed stability (handy in an luxury ultra-barge). Meanwhile, the hydrogen fuel itself is stored in a tank laid down the middle of the chassis like a normal car’s transmission tunnel, with the power control unit under the bonnet and batteries shoved in the rear to balance the weight distribution.

Lexus is indeed working on next-gen self-driving tech that will allow the new LS’s electronic brain to monitor all 360 degrees of its immediate environment, enabling totally autonomous motorway lane-swapping and hands-free cruising.

Sounds like Tesla’s Autopilot function, wrapped up in a car that’s even more tech-heavy. Could this be the first LS since the original to shake up the luxo-barge establishment? We’ll find out in four years.