The windscreen pillars on many cars often do not have the vinyl on them, or else they are covered with material salvaged from the offcut from the original sheet that was used to make the top, & joined with a stitched seam at the top of the pillar. This is how the original top on this car was done.

It's done this way to avoid the extra wasteage of about a meter of material when the whole thing is made from a single piece, but making it in one piece removes a possible source of water leakage under the vinyl, & i think it looks better, .. so i spent the few extra dollars & got the job done properly.

If you look carefully you can see that the seam on the roof is not stitched. It's welded instead, so there will be no leakge there either.
KB10, it's no ordinary car.