I would definitely get a targa top or T-top even if it were an extra couple thou. Screw body rigidity. I don't plan on racing on the Nacar circuit. Besides, the new chassis has a bazillion-load more rigidity than the old one, and I never had a problem with the old one. I'd be willing to be 99% of people wouldn't know the difference anyway.
That's one of the reason I don't own a Mustang any more. Cheap interior and no available moon roof. I see they fixed the interior problem, but what of the roof? A Targo or T-top would be sweet. Got a 2003 Tiburon GT now and can't wait to get back into a Mustang. Nice car, but driving wasn't the same anymore.