Hubley did indeed put out a series of 1:20 scale die-cast metal car model kits that are just about spot on, size wise. The chassis and bodies are diecast metal castings (which require considerable work with a file to remove flash) and the detail parts are plastic, some are brass-colored chrome plated. The tires are real rubber. Just as the originals were, all of these autos were built on the same chassis, but with different bodies.
As Bruce mentioned, while no longer in production, they can still be found sometimes on eBay. Another possible source is my friend, Clem O'Jevich - proprietor of the Warrior Run Locomotive Works
, which can be found online here
. He had a few to sell at the last Train Show in Timonium, Maryland, a couple of months ago. At a pretty reasonable price, too.
I model a period exactly 100 years ago (right now it's about to turn 1912 on my Fn3 railroad) so Hubley's line of early Model T Fords fit in perfectly. Even if you model a later period, there were still plenty of "Tin Lizzies" - as they were called - running around as late as the the '30's and '40s.
Here's some models I built from those 1:20 Hubley kits. They are some of the few models that are both fairly accurate and very close to proper "F Scale" size.
This one was known as the "Runabout."
This is the "Touring Car" - probably the most popular model.
This delivery van was also very useful.
Good luck on your search, and Merry Christmas to everyone.