The Alfa Romeo 12c was a 3 Litre Class Grand Prix car developed in 1938 from the earlier 8c.
The 12c was very short-lived however as the 308 was already designed to replace it during the same year.
WW2 ended this era of Grand Prix cars, and although they did return post-war, rapid advance in design changed them forever.
This example is the 12c/312, with the V-12, 3 litre engine.
Hehe nice, the great Fangio won some races with it.
Yet again, Clave, a truly beautiful image. Thank you for posting it. 
I wonder what the Mercedes Benz W 133 or W 136 would look like, next to it.
Since the German vehicles were used as ground-test machines for the DB 600 and 601 series engines, I have had a mild interest in them for years, mainly because the motors themselves are now comparatively rare.
Kindest Regards, Uyraell.