Prepare a medium fire and place the grill 6 inches above the coals. Place the 4 tablespoons of oil in a bowl and mix in the chopped garlic. Brush the peppers, onions, and corn with oil and season with salt and pepper. Place the peppers on the grill (cut side down) and cook for about 4-5 minutes. Turn on the grill for an additional 2 minutes. Be careful the skin does not become too charred. Remove the peppers and julienne. Place the onions on the grill and cook for 3 minutes on each side. Remove from the grill and chop into 1/2 inch pieces. Place the corn on the grill and cook for 1 minute. Rotate the corn and continue to grill (it should take about 3 minutes to cook on all sides). Remove from the grill and remove the kernels from the cob with a knife. Place the sausage on the grill and cook for about 4 minutes on each side. Sausages should cook in about 6-8 minutes. Place the julienne peppers, chopped onions, corn kernels, and chopped tomatoes in a bowl. Add basil, remaining olive oil and vinegar and toss. Season with salt and pepper. Divide salad into six plates and place two sausages on each plate. Serve with crusty Italian bread.