Start year at 1935 at 1940 for America not the rest.
viewtopic.php?f=14&t=5237
And daffyflyer's reply:

It is actually wrong it didn't start at the 1940's it started at 1935 and 1940 is a little to late because if you start to plat in america you only have one year to develop car which is too short or if it's outside you cannot make cars and all countries have to switch to military production for the effort to stop the nazi or if you are in the axis you have to go to miltary production to stop the ally.And It's really 1935 which is really started to have that's when the modern style of car manufacturing really started to take off. (bodies without seperate wings, more mass production and less coach building), and so we could focus our efforts on a narrower spectrum of cars and do it right.And here is proof from a 1935 Chevrolet ad:

And here is proof that is not the 40's and they only did that in American because the rest of the world is in World War II but not america until 1941 and please put like if you are in america it's 1946 and if you are outside america 1946 so it makes more sense.