In a large microwave safe bowl melt the margarine for 1 1/2 minutes. Remove from the microwave and add the rest of the ingredients. Mix well. Place back into the microwave and cook on high for 5 minutes. Take the bowl from the microwave and stir well. Continue cooking on high for an additional 5 minutes, remove and stir. Cook for 3 more minutes ( for a total of 13 mins.) Remove from the microwave, stir in vanilla and pour into a 9 x 13 pan to set. Once caramel has set, sprinkle with sea salt and wrap in wax or parchment paper and store in an air tight container.