666 no not the number of the beast, it stood for 6 cylinders, 6 seats and 6 gears. This was produced as a prototype in 1947 by French company Mathis and had a few innovative features. One was mentioned in its name, it came with a 6 speed gear box, which is very modern by todays standards. The other was that 6 cylinder 2.4ltr engine that was a boxer unit and mounted up front and drinving the front wheels.
The engine was later replaced by a 2.8ltr unit for its
appearance at the Paris Auto Saloon in 1949. It even appeared in the Mathis
sales brochure for 1949/50 with 3 body styles however none got past the artist impressions.
As you can guess it didn't go into production but there no denying it’s interestingly styled, awkward in a strongly
charming way, like it was drawn by two different designers who did the front
and rear separately. I’ve not been able to find out much more about it, so if you know more please get in touch.