The “sporty” version of the Peugeot 207 is known as the “serie’ 64”. It has door badges with the number both in numerals and spelled out. The seats are also embroidered with “64” in a circular logo (64)
I am curious if this is a cultural reference perhaps an iconic road (like route 66 in the US) maybe the number used by a French racing driver, or perhaps a significant year. (maybe a superior wine vintage?) There is the Beatles tune, but I don’t see how that works into a car image excepting perhaps midlife crisis?
Googling is no help. Of course it could be a exercise in branding something completely arbitrary.