Prior to the popularization of unibody construction in the 1960s, many independent coachbuilders built bodies on rolling chassis provided by luxury or sports car manufacturers, both for individual customers and makers themselves.
The manufacture of necessarily fragile, but satisfactory wheels by a separate trade, a wheelwright, held together by iron or steel tyres, was always most critical.
[4] The coating of the interior of the coach with leather and painting, trimming, and decorating the exterior called for specialist tradesmen with a high degree of skill.
From the beginning of the automobile industry manufacturers offered complete cars assembled in their own factories commonly using entire bodies made by specialist people using different skills.
Soon after the start of the twentieth century mass production coachbuilders developed such as Mulliners or Pressed Steel in Great Britain, Fisher Body, Budd, Briggs in the U. S., or Ambi-Budd in Germany.
Many coachbuilt chassis would come with all lights, standard instruments and their panel, engine cover, mudguards and running boards and spare wheel(s)[citation needed]There remained a market for bodies to fit low production, short-run and luxury cars.
The car manufacturer would offer for sale a chassis frame, drivetrain (consisting of an engine, gearbox, differential, axles, and wheels), brakes, suspension, steering system, lighting system, spare wheel(s), front and rear mudguards (vulnerable and so made of pressed steel for strength and easy repair) and (later) bumpers, scuttle (firewall) and dashboard.
The very easily damaged honeycomb radiator, later enclosed and protected by a shell or even reduced to an air intake, was or held the visual element identifying the chassis' brand.
To let car manufacturers maintain some level of control over the final product their warranties could be voided if coachbuilders fitted unapproved bodies.
Larger car dealers or distributors would commonly preorder stock chassis and the bodies they thought most likely to sell and order them for sale off their showroom floor.
Other examples include the Bugatti Type 57, Cadillac V-16, Packard Twelve, Ferrari 250, Isotta Fraschini Tipo 8, Hispano-Suiza J12, and all Rolls-Royces produced before World War II.
Independent coachbuilders survived for a time after the mid-20th century, making bodies for the chassis produced by low-production companies such as Rolls-Royce, Ferrari, and Bentley.
The advent of unibody construction, where the car body is unified with and structurally integral to the chassis, made custom coachbuilding uneconomic.
Many coachbuilt chassis would come with all lights, standard instruments and their panel, engine cover, mudguards and running boards and spare wheel(s) [ citation needed ]