necessity of a roof

[amalventano1 at tds.net (Allyn)]

So long as the side rails remain, removal of the center sheet of steel should have a negligible effect.  It is the tying of the A,
B, and C pillars that give the extra rigidity, and the side rails have significantly more rigidity than the thin roof body panel
itself.
HTH
Al


>    i know that there are convertible sciroccos and cabriolets 
> with extra body support rolling around out there with for the 
> lack of a steel roof. 
> but, what i'm wondering, would extra support be necessary if 
> the frame of the roof is there and not the middle section? in 
> essence, to convert the roof into one big sunroof? 
> harebrained, i know. i just see these ads for new cars with a 
> vertical sunroof rather than a horizontal one and wondering 
> if the middle man couldn't just be skipped. now, on with normal life.