Preheat oven to 325 degrees F. Grease a bundt cake pan or spray with non-stick coating and wipe excess out with paper towel.
In large mixing bowl combine cake mix, water, oil and eggs. Mix well on low until blended. Mix on high for abouat 2 minutes. Stir in bacardi rum and blend on low till thoroughly blended.
Place chopped pecans in bottom on bundt or baking pan evenly. Pour cake mix over nuts. Place in oven and bake for approximately 1 hour at 325 degrees F.
To make glaze, using a small saucepan combine melted butter, sugars, rum and 1/4 cup water. Stir well and bring to a full boil. Boil 3 minutes. Remove from heat source and set aside.
Remove cake from oven and transfer to a cooling rack for about 15 minutes. Run a wet knife around the edges to loosen. Upend on lipped serving platter or cake pan. Poke holes using toothpick in top or cake. Pour warm glaze over. Allow to set before serving or wrap in plastic wrap and store in fridge until ready for use.