Preheat oven to 350%. mix together the beef,bread crumbs,onion,egg,salt,pepper and 1/2 cup tomato sauce. form mixture into a loaf and place in a shallow pan. stir together the remaining tomato sauce,vinegar,sugar,mustard,worcestershire and the water if to thick. pour the sauce over the meatloaf. bake for 1 hour, you want to make sure your basting every 15 minutes or so with the juices from the pan. if you have left overs i love making this into a sandwich with mayonnaise.