This is Volkswagen's multibillion dollar, six-year engineering odyssey that you'll never see again in millions of cars around the world.
Called the MQB platform, it is about to provide the basic architecture for everything from Audis and Volkswagens to Skodas and Seats.
The MQB will arrive first, unseen, beneath the all-new Audi A3 at the Geneva Motor Show later this month, followed by the next Golf soon after.
The German acronym for Modular Transverse Matrix, the MQB will find its way beneath everything from the next all-new VW Polo to the next VW Passat, from the Audi A1 to the Audi A4.
Besides saving around 60kg on the current Golf's architecture, the MQB is also made from hot-formed steels that are six times stronger than the usual steel sheets, uses simpler, lighter electrical systems and has more aluminium in the suspension.
But it won't stop there, as it's been designed to quickly have cost taken out of it for cheaper brands such as Skoda and Seat and more put in for Audi.
Even before it finds new niches, just replacing existing models in the VW Group's current lineup would involve the Polo, Beetle, Golf, Scirocco, Jetta, Tiguan and Touran, all the way up to cars the size of the Sharan and the Passat.
VW claims the MQB is a turning point in transverse-engined chassis design, because it has been standardised for so many different technologies at so many different prices.Not only will all of these models be built off the same architecture, but they could also, theoretically, be built on the same production line, at the same time.
There is a hint of a mega factory in the future for VW's smaller machines, in spite of different wheelbases and track widths.
The MQB will not only allow for different sizes of cars, but it's also pre-engineered for a range of safety innovations, electrical architectures, different drive systems and it's even future-proofed for consumer electronics innovations, such as iPad-style devices instead of MMI displays.
Even the VW Group's designers love it, because it stretches the distance between the front wheels ahead of the windscreen pillars and reduces the need for front overhang, which allows them to put cleaner proportions on their body shapes.
There have been plenty of previous chassis that could be stretched or shrunk to accommodate bigger or smaller cars, but this architecture will slash the VW Group's costs by also stretching and shrinking the same electrical wiring systems, the same engines, the same transmissions and the same ventilation setups.
The MQB will be based around the exact same engine mounting points for every car it sits beneath, including two all-new modular VW Group engines.
The EA211 petrol engine range works at outputs from 40kW to 110kW while the EA288 diesel engine range will stretch from 88hp to 188hp of power. Between them, they will slash the engine and gearbox complexity on VW production lines by around 90 per cent.
The MQB has also found space for existing and (some) future drive systems, such as natural gas, electric drive and hybrid drive, and the Golf will have a 20kW electric motor when its hybrid debuts next year.
It also rings in safety changes with a new trick called Multi Collision Braking, by automatically braking the car after a collision to minimise further injury risk.
But the MQB philosophy is not unique to the VW Group, because it already has the MLB (Modular Longitudinal System) for the A6 and A7, the Modular Standard System from Porsche and the new architecture beneath the SEAT Mii, the Skoda Citigo and the VW Up!