Decades ago, American convertibles ruled the roads. But lately it seems that fewer ragtops are rolling through my shop; and the ones that do are all made overseas. Curious as to why, I did a little research and was shocked by what I found.
In 1968, the "Big Three" produced 53 convertible models. In 2011, they combined to produce a total of six. That's a whopping 89% decrease.
Why the significant drop? Check it out: http://tinyurl.com/d5g4pv2
I see alto now that are convertible hardtop like the Chrysler Sebring for example.
The uni-body has made the roof a necessary integral part of the construction of the car. Even the type of adhesive used to install the windshield is an important factor in the strength/ rigidity of the car. Not that it can't be built but it takes a lot more engineering than just cutting the roof off and installing a rag top! Then comes the liability/ safety factor of building this inherently less safe design.