Hello,
I made this morning the assembly jig for the roof and the sides of the car; now I let it dry before gluing these parts together!
It's made of cardboad; the roof is held in place by 4 little pieces of cardboard at each side of the jig and verified with a spirit level and locked with clamps; then the side is inserted between the vertical part of the jig and the luggage rack (in brown) to be glued.
Once glued these 2 parts will be turned to 180° to glue the other face to the roof.
Easier to write than to do!
jpv in France