Well, it was done purposely, to install a Webasto-style folding fabric sunroof. The manufacturer, SlidingRagtops.com, said it takes 4 to 6 hours to install; try more like 12 or hours! And we're still working on sealing the edges against rain and weather, although the rattling latch has been fixed with a temporary but effective solution. Overall, it's a lovely enhancement that provides open-air motoring with much less trouble than a folding or stow-away convertible top. Many MGB/GTs in England had dealer-installed fabric sunroofs, but for some reason, the custom did not cross the pond.