Google Books again came with another big thing, by putting online all the issues of Popular Science Magazine, since the very first one issued in May 1872!
I assume, as you're browsing through ShamWerks, that's you'll be especially interested by the issues from the 50's-60's. And good news, these are just an orgy of shiny retro-futuristic covers!
More specifically, you'll find for example in the June '57 issue a comparative test of "foreign cars", featuring the Karmann Ghia Low-Light (on the cover), the BMW Isetta, the Renault Dauphine, etc... And in the April '58 issue, that's a Beetle you'll see on the cover, illustrating an article about the "8 best-selling cars"...
Furthermore, in the February '67 issue, you'll find a pretty nice article about "the cars you can build yourself", the main feature being the Manx Buggies! (wow, Bruce Meyers was young on these pics! ).
Yet more buggies on the cover of the August '69 issue, as of the March 69 issue (along with an article by Wernher Von Braun, funny to see how they forget the SS past of that guy 'cause he took'em on the moon... Whatever...).
I could keep on going giving you a list of links, but the best way to find out if for you to dig into it by yourself : Click here! Thanks who? Thanks Google.