A bit pricey, but here is a link to a die cast model of a 1948 Hudson:
http://www.eautomobilia.com/pr...1948-NEO-143-Diecast
Here's a photo of a 1949 die cast Ford Convertible:
http://passiondiecast.com/en/m...ord-convertible.html
Contrast this to a 1951 Chevy with the old style design:
http://www.nicecardiecast.com/...1952-convertible.cfm
Here's a 1950 Cadillac Convertible:
http://www.diecastmodelswholes...r-by-road-signature/
Here's a picture of a 1950 Plymouth the article that is titled: "Solid but outdated: Plymouth 1950 to 1954."