1) For dressing, combine vinegar, garlic, oregano, and salt in a small bowl; whisk and set aside.
2) Prepare vegetables and brush with oil. Snip parsley and set aside.
3) Meanwhile, bring 4 quarts of water to a boil. Cook pasta according to package directions; drain and keep warm.
4) Place vegetables on grill. Grill onion 10-12 minutes and romatoes, eggplant, zucchini and bell pepper 6-8 minutes, uncovered, turning once.
5) Remove vegetables from grill; cut into bite size pieces. Place vegetables in large bowl; drizzle with dressing and mix gently.
6) Place pasta in large shallow pasta bowl or platter. Spoon vegetable mixture over warm pasta. Sprinkle with parsley. Serve with parmesan cheese if desired.