BMW has offered a rare glimpse into the inner workings of its Pilot Plant in the heart of its Research and Innovation Centre. It is here, under tight security and in the utmost secrecy that the iNEXT prototypes are being built for testing, and to help BMW get ready for series production.

Of course, the BMW iNEXT isn't due to go into full production until 2021, but there's a huge amount of work to do in the meantime around everything from perfecting new materials, through to ensuring that each part is produced and fits with absolute precision. This means that the plant is already knocking out prototypes which are being used in evaluation.

Udo Hänle, head of Production Integration and Pilot Plant, said: “Preparing a fully electric vehicle for series production is an exciting but challenging task. By the time of the official start of production, we will have built as many as 100 prototypes of the BMW iNEXT. Until then, the Pilot Plant will use a range of new innovations to streamline and speed up our processes even further. We are also already preparing our first production associates from Plant Dingolfing to work on the new product.”

Some of the 100-or-so prototypes will be used for autonomous driving function, vehicle sensor and driver assistance validation. You can also bet that a few of them will meet a sticky end along the way in the name of safety. But all of this effort is helping BMW to become more efficient and test manufacturing techniques that are making their production debut on the iNEXT.

An example of this manufacturing innovation on the iNEXTs being made at the Pilot Plant is rotary bonding. This process uses the heat from friction generated as a steel component pierces an aluminium one to literally fuse the parts together. And to check that assembled bodies are meeting exact perimeters, BMW is using laser scanning which removes the need to place measurement points manually on the car. The result is a dramatically quicker and more efficient process that can be taken into series production.

Further scanning is undertaken of completed body shells and, using a brand new augmented reality app, the picture that is created can be compared to the CAD model of an individual part or an overall section. This is so detailed that even the bolts in the car floor are scanned and compared to CAD models. Again, this speeds up the process and allows different specialist departments to work more cohesively.

There is one last notable technology that BMW is implementing on the iNEXT at the Pilot Plant is X-ray. Four robots undertake a merry dance around the car in two pairs, sending their scans to their opposite. This allows BMW to see the layers within the shell and – without dismantling anything – check that parts fit together properly and that fancy rotary bonding is up to scratch. Such is the detail that the X-rays can 'see' if one of BMW's technicians shed a hair if one was to end up within the body shell.

Looking at the pictures, the iNEXT prototypes are clearly nearing production-ready and BMW is now on the final stretch of making sure its house is in order. We've not had any further detail in terms of technical specification, but what we have is still tantalising: 372 miles of range, level three automated driving and BMW's fifth generation eDrive technology. No doubt we'll hear more very soon.