In a medium saucepan, whisk together the chili sauce, wine, oil, lemon juice, basil, sugar and garlic.
Heat mixture just until warm and slightly thicker. Add prepared shrimp. heat through... do not boil or they will be tough. Turn off heat and let set for 30 minutes, stirring occasionally.
Heat grill to medium heat. Remove shrimp from pan, reserving sauce. Thread shrimp onto 4 or more skewers and grill for 4 to 7 minutes, or until heated through, turning often and basting with the reserved sauce during the last 3 minutes of grilling. Sprinkle with chopped fresh basil leaves.