It's not factory, but it's vinyl installed to help sell cars:


The Stallion:

 

That Stallion looks like a Mercury Cougar to me. Typical Canadian screw up of a perfectly good Shelby. Yeah, the cougar had a bunch of vinyl topped cars. I owned a 68 with a vinyl top. That was Mercury's answer to the Mustang, but with a few more luxury items. Mustang came back with the Grande to quell the competition.