I think you're right Harold. A lot of it was due to increasing governmental safety regulations that were just gaining momentum at that time. That, and parts availability, as GM would use up early parts before switching to new. The one-sided satin was obviously to reduce sun glare to the driver and passenger, while the shiny, chrome side would still be visible from the front, complementing the chrome windshield frame.

Speaking of safety regs, I distinctly remember the Pontiac salesman in January 1968 telling us that we should buy the car off the lot right now because if we waited and ordered from the factory we would probably have to have shoulder belts in the convertible. How inconvenient and costly that would have been! So, how many of you have shoulder belts in your 68 verts?