The 1940s featured many great cars. The 1940 Plymouth, the Chrysler Town & Country Wagon (the original "woodie"), the Lincoln Continental, the Delahaye, and the Cadillac Series 62 were some of the more popular and cool cars of the decade.
good cars
bmw
not very
Cars were fairly common at this point. In Germany they were working hard on the Volkswagon, or 'people's car'. There are lots of great sites about the 1940s. It won't be too difficult to look up some more about this era.
ugly cars
Cars and carriages.
Awesome cars that went bang when they hit something instead of crunch
there is a lot of cool cars on are earth
If the one they are for likes cars, and has some smooth space to race them, they are very cool.
flying cars.
Cool blue cars? if it is cool blue cars then yes it is legal