Put the cereals and pretzels in a large roasting pan. Melt the margarine and add the garlic salt and garlic powder. Pour the melted margarine and garlic over the cereals and mix well. Bake in 200 degree oven for two hours, stirring (be sure to get the cereal at the bottom of the roaster) every 1/2 hour. Add the cocktail peanuts and cook 1/2 hour more.