Notes:
Established in Paris by Marcel Gendron, Gendron & Cie. produced automobile parts such as transmissions, rear axles and steering columns, since 1910. Marcel Michelot was the company's sales manager. Later the duo founded Automobiles Gendron & Michelot, mostly known as G.M. (an acronym for their initials). Series production of a 1.1-litre automobile began in 1924 and the next year the 1.5-litre GC2 model was presented.

That same year te make took part in the third edition of the 24 Hours of Le Mans, with two G.M. GC2 cars. Marcel Michelot, who was a talented amateur driver, completed 101 laps and finished 15th overall, sharing one of the cars with Adrien Drancé; Marcel Gendron with the the company's test-driver Lucien Bossoutrot as team mate, did not finish the race. In 1926 the team did not participate in the race.

Two G.M. GC2 cars were in the entry list of the 5émes Grand Prix d'Endurance les 24 Heures du Mans, scheduled to be held on 18 and 19 June 1927. Once again one of the drivers of the cars was Marcel Michelot.

During a practice session one week before the race, Marcel Michelot went out to test one of the cars during the night between Sunday 12 and Monday, 13 June 1927. After enjoying dinner at the Hunaudières restaurant, he started his run in the dark.

Almost three hours later, on Monday early morning, he lost control of the car while approaching the Arnage esses. Reportedly, the accident occurred in heavy fog, the car went off the track on the left side and collided with a oak tree. The driver suffered massive head and chest injuries from which he died almost instantly. Marcel Michelot was 34 years old.

Marcel Gendron, the G.M. general manager, was in the pits acting as timekeeper. In consequence of Michelot's death, he decided to withdraw all the G.M. entries from the event, and the whole team, cars, drivers and mechanics returned to Paris the following day. Production ended in 1928.

• Newspaper L'Ouest-Eclair (Rennes, Bretagne, France), issue of Tuesday, 14 June 1927, article "Le directeur commercial des automobiles G.M. se tue sur le circuit de la Sarthe pendant un essai", page 4, retrieved by website http://www.ouest-france.fr/services/ouest-eclair.php .
• Website The Fastlane, article "Unknown 1920s Le Mans Wreck", page: http://www.the-fastlane.co.uk/phpBB2/viewtopic.php?t=1787 .
• Website Racing Sportscar, page http://www.racingsportscars.com/make/G.M._.html .
• Website Motor Legend, Forums Auto de Motorlegend > Sport auto / Loisirs > Forum Endurance & Protos, thread "Les projets LE MANS avortés", posting by "dilettante", message http://forums.motorlegend.com/vb/showpost.php?p=505234&postcount=24 .
• Website Motor Legend, Forums Auto de Motorlegend > Sport auto / Loisirs > Forum Endurance & Protos, thread "Les non-partants des 24 heures" page 25, posting by "Haine Kane", message http://forums.motorlegend.com/vb/showpost.php?p=403724&postcount=495 .
• Website Pre War Car, page http://prewarcar.com/previous_features.asp?FirstRecord=1586&e=108 .
• Website Le Mans & Formula 2 Register by Stefan Örnerdal, page http://www.formula2.net/1925.htm .
• Website Le Mans & Formula 2 Register by Stefan Örnerdal, page http://www.formula2.net/1927.htm .
• Website 24h-en-Piste, page http://www.24h-en-piste.com/fr/AfficherPilote.php?Pilote=1885 [incorrect date of death: 13 July 1927] [S1].
• Website BNF Gallica, page https://gallica.bnf.fr/ark:/12148/btv1b531593796.item .
• Website Wikipedia, page https://de.wikipedia.org/wiki/Gendron_et_Compagnie .
• E-mail by Andrei Sidorov, dated 08 September 2019, citing [S1].