I bought a glasfiber rear decklid secondhand. It allready had the inner frame from a normal metal decklid glassed in:
A guy that dealt a lot with glassfiber parts told me not to use the rear decklid spring anymore. The spring is to strong for the lighter rear decklid.
I hammered out the hinge pins, and replaced them with the hinge pins of a normal house door hinge. These were just a little bit smaller in diameter, so they would slide in quite nicely.
Now I can remove the rear decklid in seconds, and replace it without having to adjust the decklid again.
The result:
Maybe I will have it painted in the car's color someday...