In a glass baking dish toss the shrimp with the garlic, chilies and olive oil. Cover and marinate, refrigerated, for at least 24 hours. Preheat grill or broiler and cook shrimp, brushing occasionally with marinade, for 2 to 3 minutes per side.
In a small bowl stir together 1/2 cup olive oil and red hot pepper sauce, to taste.
Serve the hot grilled shrimp with the dipping sauce.