You might imagine that the forward-pointing chevron pattern symbolises Citroën's forward-looking, advanced approach to engineering.
But no: André Citroën started in the motor trade by building gear wheels, and the twin chevrons are meant to represent gear teeth.
Citroën was founded by André-Gustave Citroën. Did you know the Citroën name actually comes from the name lemon?
André-Gustave was the 5th and last child of the Dutch Jewish diamond merchant Levie Citroen and Mazra Kleinmann. The Citroen (Dutch for lemon) family moved to Paris from Amsterdam in 1873. Upon arrival, the diaeresis was added to the name, changing Citroen to Citroën (a grandfather had sold lemons, and had changed the consequent name Limoenman 'lemon man' to Citroen 'lemon' in Dutch).
This Citroën logo was restyled and replaced in 2009.