Ding, ding, ding, ding, ding, ding, ding...................
Eric and Garin would be correct.
I actually hacked it out of my car as part of the final plans include some welded metal structure between the B pillars and down across the floor for the purpose of tieing the seats to the seatbelt frame and a four point harness. Heck, a Kia at 150 mph would be safer than my car at 25 mph, but anything has got to be better than that half breed last minute thought structure that you have now identified.
It really seems to me that in a bad accident, the cable mount would pull out of the opposing floor board and be able to slip about 4 to 5" before catching in the welded tab in the frame. Providing the impact force is great enough, that would continue to slip through escpecially if you are pushing a solid 190 lbs like me.
I suggest anybody with a C3 coupe check out the roll cage offered by JEGGS Performance for around $300. It is a four point mount and you can hook a saftey harness direct to that and eliminate that scary stuff from the factory. Plus it looks cool. Unfortunately, there is none that I am aware of as a direct bolt/weld in for the rag tops. That is why I will be having a custom one built.
Thanks Eric for the answer and to retro75 for asking.
