That would seriously compromise the structural rigidity of the car. For a show vehicle that isn't driven much, it'd be ok, but the handling would definitely suffer and you'd probably hear creaks and groans from the body after a while.
I'd recommend at least a center bar remain in the roof like the 300Zs had. This would retain longitudinal stability and some of the torsional. Another alternative would be a 6 point roll bar.
