Neat find! I don't remember ever seeing those before.One thing that puzzles me though is the address on the back.As I remember Hot Rod Magazine was published by Petersen Publishing and their address was 5959 Hollywood Boulevard.That address(5954)would be across the street.Maybe a misprint.
I think that card with the red A touring in the snow is from a photo shoot that was taken for the cover of one of the '64 issues.
The business office was across the street from 5959. Torco Oil put out a some trading cards that were a bit larger and were called the Torco Wall of Fame trading cards. Ran into some serious problems with complaints from parents when the owner of Torco put little New Testiment bibles in with the trading cards. HOT ROD and CAR CRAFT had us pull the ads!
Royalshifter is correct, 66 cards altogether. There are various stories as to how they were distributed. From being inserted in the magazine to other giveaways. One of the biggest things is that they were printed on "plain" cardboard (read: cheap) as compared to baseball cards at the time. This meant they had more of a tendency of delaminating so finding a complete set in good shape can be difficult Definitely neat stuff.
While cleaning out my parents house I found my old set of these. It brought back good memories looking through them.
I still have all of mine from when I was a kid. I need to scan them (like some many other things I have).
Here's the thread that I started a few months back looking to do some trading for the Hot Rod Cards that I needed to complete my set. There's a couple members, myself included, who still need to fill in a few gaps and have some duplicate cards to trade. http://www.jalopyjournal.com/forum/showthread.php?t=496331 Feel free to post to this earlier thread if you've got any worthwhile swapping material. Prefer to do "one for one" swaps. As I remember, the cars were packaged maybe 4 or 5 in a wax paper wrapper with a big slab of stale bubblegum, just like baseball cards.