Grease and flour 13x9" pan. Preheat oven to 350~. Blend cake mix, margarine, 1/3 cup evaporated milk, and pecans, just until moistened. Press 1/2 the dough into the bottom of the pan. Bake 6-8 minutes. Melt caramles and the remaining evaporated milk in top of double boiler. Sprinkle chocolate chips over top of baked cake mix. Spread with melted caramel mixture. Take small pieces of the remaining dough and pat then flat between your hands. Lay these flat pieces over caramel layer. Caramel will not be completely covered. Bake 15-18 minutes. Cool and cut.