This C pillar brace is specifically designed to stop body flex on the back of the 944.
This flex during cornering allows too much weight shift in the rear, destroys the rear window seal, can cause cracks and deform the body. Whether from the track or just driving the car like it should be...a little hard. Born, bred, and tested on the track. 
 This is a performance upgrade with a cross benefit. The back windows always come loose up at the top because of the body flex in that area. This supports that area as a compression/tension brace and keeps it from uneven snap load weight distribution,
 INSTALL :
Simply take the plastic Phillips plastic plugs out or in some cases remove the rear seat belt bolt and slide it in. Tighten the bar load hand tight and use the supplied nuts to lock it in place.
 
** Black Anodized pictured in pictures 6 & 7 and may take an extra week to ship