Everybody has two axles so why not simply take three of them instead of two - but only if you need them!
It's that third axel with two wheels that is the key feature of the innovative modular mobility system from Swiss automotive visionary Frank M Rinderknecht and we'll get to see the vehicle at the Geneva Motor Show next March at the Rinspeed stand.
'Dock+Go' is the name given to this 'backpacks on wheels' concept.
These 'packs' can be used for many purposes, depending on your requirements of the day, for work of play. They also solve the operating range problem of electric vehicles in a very clever way - neither unneeded space nor superfluous weight is carried along if they're not needed.
The vehicle would have a 120kms range, but an 'energy pack' with a combustion engine or range extender, packed with batteries or powered by a fuel cell, gives added range.