Carrozzeria Scaglietti was an Italian automobile design and coachbuilding company active in the 1950s.

Carrozzeria Marazzi is an Italian coachbuilding company founded in 1967 and is located in Caronno Pertusella, outside Milan.

Carrozzeria Ghia SpA (established 1916 in Turin) is one of the most famous Italian automobile design and coachbuilding firms.

Pietro Frua (2 May 1913, Turin, Piedmont - 28 June 1983) was one of the leading Italian coachbuilders and car designers during the 1950s and 1960s.

Carrozzeria Fissore was an Italian coachbuilder located in Savigliano, near Turin (Piedmont).

Carrozzeria Castagna is an Italian coachbuilding company based in Milan, Italy

Carrozzeria Boneschi S.r.L. (established 1919 near Milano) is an Italian coachbuilder, mainly of commercial vehicles.

Gruppo Bertone, commonly known simply as Bertone, was an Italian automobile company, which specialized in car styling, coachbuilding and manufacturing.

Carrozzeria Allemano (established 1928, discontinued 1965) was an automobile coachbuilder in Turin, Italy, owned by Serafino Allemano.

Knocking (also knock, detonation, spark knock, pinging or pinking) in spark-ignition internal combustion engines occurs when combustion of the air/fuel mixture in the cylinder does not start off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front.