After WW II automotive mass production soon became mainstream, ending the era of separate manufacturing of chassis and tailored coachworks. Many coachbuilders went bankrupt, were bought by manufacturers or changed their core business to other activities.
- transforming into dedicated design / styling houses, subcontracting to automotive brands (e.g. Zagato, Frua, Bertone, Pininfarina).
- and/or transforming into general coachwork series manufacturer, subcontracting to automotive brands (e.g. Karmann, Bertone, Vignale, Pininfarina).
- manufacturing of special coachworks for trucks, delivery vans, touringcars, ambulances, ‘voitures des pompiers’ (fire brigade), public transport vehicles, etc (e.g. Pennock, Veth &Zn, Akkermans, Heuliez).
- becoming technical partner for development of e.g. roof constructions (e.g. Karmann, Heuliez) or producer of various (aftermarket) automotive parts.
Meanwhile many car manufacturers established inhouse design departments themselves, increasingly developing their own design and styling DNA.
Former distinguishing brand elements indicating the brand’s styling genes (like the external radiator/grille) now became integrated in the overall design.
Many characteristic styling features of specific coachbuilders were even adopted by car manufacturers as their own ‘brand elements'.
Surviving independent design houses / coachbuilders were hired by car manufacturers for designing their series produced models.
Regularly they were also hired to design (and sometimes build) the (official or semi-official) niche models, based on the underpinnings of existing series produced models.
Many times coachbuilders created wonderful designs still on their own initiative, resulting in streetlegal prototypes which were often sold as “one-offs” to wealthy clients.
Frua Maserati Quattroporte 'Aga Kahn'
Initially (’40 – ’50 – early sixties) design houses / coachbuilders could still purchase separate chassis on which they could fit their own inhouse designed coachworks. Not without reason: many wealthy customers still commissioned their special one-offs based on ‘current’ available rolling chassis (then state-of-the-art), or even based on other series produced cars.
Productionwise the early days were relatively easy as chassis and coachwork were independently constructed. Hence the term “rolling” chassis. In the sixties however the monocoque and spaceframe constructions were introduced, which made it significantly more difficult for coachbuilders to fit newly designed bodies on a donor chassis / car. Freedom of (coachwork) design became more and more limited due to the predefined shapes of given body structures.
Peugeot 404 monocoque and drivetrain
The chassis no longer acted simply as a flat undercarriage as it now also comprised the stressed roofline constructions and other stressed body panels (window pillars, rear fenders, and recently even the windows themselves).
From now on coachbuilders had to deal with the integrated stressed structure of a car which essentially determined most basic bodyshapes.
Also safety regulations became more stringent, resulting in many technical requirements prohibiting most chassis modifications. So again the coachwork designer’s freedom became more limited. This forced design houses / coachbuilders to limit their rebody scope of work primarily to the outer panel work, necessarily leaving the basic car structure and proportions untouched.