I sometimes wished I had one for a convertible project as they just need the doors welded up halve way and just have halve height doors in fibreglass with Lotus 7 style windscreens.
Also a big bore 2 litre notchback style VW engine in the rear with subaru box and side inlet manifolds fed by a snail to keep a flat tray.
The front would just have storage space under the bonnet.
Instead of the heavy tailgate you could just have some scratch proof lexan with chrome surrounds, Chrome the grille as they are tin and get the deluxe sedan stainless chrome window trim surrrounds.