My Boxster is a 1998. I have a small black plastic pull tie on each of the black plastic roll bar inserts that hopefully will keep them from flying away if I hit a bump or something.
The one on the passenger side of my car is missing pieces. I believe over time the plastic becomes VERY brittle from baking in the sun for decades, if I accidentally hit the one on the passenger side more of the holes are broken off. I've thought of trying to cast them in aluminum or some kind of plastic, some kind of last wax method maybe, but haven't researched it much and I don't want to spend the outrageous price they'd want for a new replacement as each side is unique I believe and I don't want a "used" one because they are probably just as brittle as mine.
