not sure How much more you want to extend your top but I would imagine thats its not that tall. But if it is....The roof is two parts I would think that in order to do it right the fiberglass guy would have to cut back the top pieces that sits on the top cap and overhangs back a foot or so and then make a mold to extend back and be able to be attached to the existing roof and glass it back in with the old one. Few grand ought to do it.
