The rear wheel tubs are different so as to allow the roof mechanism to be stored when in the down postion. Also the trunk torsion bars are unique to a convertible. I would think it can be done but not sure if it would be cost effective .Has anyone made a Convert from a hard top.
I know the rocker would need reinforcement ( or maybe just subframe connectors???)
And the sheet metal / bracing around the back of the back seat and around the roof line where it meets the quarter and deck lid would need fabrication.
I'm %99.99 certain I'm not going to attempt. But was curious.