Prepare a 9" pie plate by rubbing inside, bottom and sides with 1 teaspoon of the margarine; set aside. Crush vanilla wafers to make very fine crumbs 1 1/2 cups. Place crumbs in a large bowl; combine vanilla and melted margarine and drizzle all over crumbs. Mix thoroughly with blending fork to make sure all is well blended. Remove about 2 tablespoons of crumb mixture and set aside to use as a garnish if desired. With back of a large spoon, press remaining crumbs evenly all over bottom and sides of prepared pie pan. Chill in refrigerator for 2 hours or longer before filling.