When did the "Certi-Card" program start?

Darwin, Dart and Barracuda are in the same place. If you look at the bottom of this picture it will show location. In 67 the certicard holder also doubled as a harness hold down.

John...thanks for that pic! I looked on my Dart, which didn't come with a holder, and there isn't even dimples for where it should be. Did only certain cars get the holder?