Before I absolutely lose it on something SO BRUTALLY TRIVIAL, can anyone tell me how the hell those seatbelt/headliner interior pieces clip into the roof? I bought a GTA with both of them missing, only to find them in the trunk and they appear to be intact. I cut a couple of slits into them to slide the seatbelt through, but I can't figure out whereabouts in the roof they clip into?!?! I am positive I have the drivers/passanger sides correct from pics I have found but... I am making a mess of the headliner.
Thanks everyone.

 

Mine wouldn't stay in because a black part of the seatbelt retractor was missing. It guided the belt through the headliner and clipped the trim pieces on it. Those may be missing.