Salut , il y a une convertible près de mon bureau (US) il faut solidifier le frame !!! Voici quelque info.
When the person who cut the roof off he/she did not do anything to support the frame so its starting to sag, not bad but enough to see the door lines are off. There are bolt in frame stiffening kits out there but are extremely hard to find or id have one. If you have the know how you might be able to build you own or stiffen the frame with some steel, . Anyways asking 1800/B.O.