The rally top isn't retractable. It is likely removable.Was the one on the rally retractable? It looks like it was stuck there to me. Admittedly, the targa top does look better on the miata than the 124... Maybe that's why Fiat is only coming out with a convertible and not a targa.
What wiring harnesses?Even if you were to remove it, you'll have all these holes exposed and openings, plus you'd have to disconnect all the wiring harnesses.
Unless they made it easy to disconnect with a cover for all the hardware.