Not all concept cars are designed by design consultancies or manufacturer´s own studios.
I have covered the work of the Pforzheim Design School recently. Today, presented as freelance concept designs, rather than as student work, here is David Obendorfer´s work. He graduated from the MOME Moholy-Nagy University of Art and Design of Budapest and has been working for the Officina Italiana Design of Mauro Micheli and Sergio Beretta for 5 years; they mainly deal with Riva boats and general ship design too. Obendorfer has taken some 70s themes and presented them in a modern idiom. We can take this to really mean designed as if produced using modern methods. The 1972 Fiat 127 is shown here updated, as if the car had been evolving these last 40 years. I´d question the little crease under the front window but other than that, it´s a lot more credible than many designs Fiat itself presents. The images are from 2013.
Obendorfer has also played around with some BMW themes, inspired by that most elegantly proportioned of cars, the 3.0 CS of 1965 . This image (above) is from 2014. While BMW have mostly eschewed retro-futurism (excepting the Z8 of 1999) these show how elastic the 60s and 70s themes can be.
What we have here then is retro-futurism, showing what happens if you separate out that element of the evolution of car design that follows engineering progress only.
Another vehicle in this vein is Renault´s 1996 Fiftie, one of the few retro cars from what automotive journalists (and only them) call la Regie.
The VW Concept 1 of 1994 and Lancia Fulvia concept of 2003 are vehicles following this line, based on existing forms. Marc Newson and J Mays applied this idea to a wholly
imaginary package and gave us a revival in the colour the car was painted in and named after, 021C, shown in 1999 at the Tokyo motor show. I note that Google search
showed as many versions showing up in Lime Green as in 021C and that colour was also noticeably more popular in the last decade than it had been before then, to the point of being a cliche.
What might be behind the phenomenon of Retrofuturism is the sense that car design had run out of open future into which it could be projected. This might explain the staleness of both production cars and concept cars of recent years.