Layering is key to the stream flow design language of BMWs i sub-brand for electrified cars, its designer, Richard Kim, said in 2011 when he came to New York with prototypes of what would become the i3 and i8.
With stream flow, which made its debut with the Vision Efficient Dynamics concept car of 2009, the body sides seem to have been sliced and folded down. The cars body appeared to be made of parts layered atop a primary, inner structure. With stream flow, BMW made a concentrated effort to create an aesthetic to match the technology and aerodynamics of the future, Mr Kim said.
Other recent vehicles with layered elements include the LaFerrari supercar, the McLaren P1 and concept cars including the Toyota FT-1, the Maserati Alfieri, the Aston Martin DP-100 and, to judge from spy shots, the next movie Batmobile.
Layering takes visible and practical inspiration from race cars and motorcycles. It also appears to be inspired by spacecraft in science fiction films. Rather than sleek monobodies, the traditional ideal, layered cars appear to be assemblies of pieces flying in formation.
The layered look has sprung from designers quest for improved aerodynamics, which are especially important in electric and hybrid vehicles. Designers, who these days speak of air curtains and air bridges, are working not only to smooth the flow of air over and around the car, but to channel air over the wheels to reduce aerodynamic drag. Often, they are feeding a stream of air under and through the vehicle.
With the Aston Martin DP-100 concept, layering serves the dual needs of reducing drag and downforce in a mid-engine supercar. Discreet, low intakes bring in cooling air, said Marek Reichman, Aston Martins head of design, replacing large grille apertures and side vents.
Active aerodynamics may soon extend to the wheels, which have important aero effects. Those on the Aston Martin concept have tiny fins that help to cool the brakes. But, Mr Reichman said, at high velocity these fold flat to reduce drag.
Layering can make a car appear lighter. In an interview with the online magazine Designboom, McLarens senior designer, Robert Melville, said: When you layer, it implies a material has been removed from underneath. It implies its lean.
McLarens design director, Frank Stephenson, described his companys approach: We want to create the most intelligent cars. A McLaren acts to different needs at different speeds, very much like an animal changing shape or colour in the wild. With the McLaren P1, we used a shrink wrapped approach. Like an exoskeleton, we were able to expose distinctive features and uncover what doesnt have to be hidden.
Mr Bangle sees todays layering as less about fabric than about time-lapse imagery. It is more about a Transformers style decomposition caught in mid-exploded view, he wrote in an email. The layers do not communicate speed or acceleration per se; we know their visual language from armour and shielding. They imply protection through lightness and overlapping.