MIX vinegar, lemon juice, dressing mix and water in cruet or small bowl as directed on package. Reserve 1/4 cup of the dressing; refrigerate.
POUR remaining dressing over vegetables; cover. Refrigerate 1 hour to marinate. Drain; discard dressing.
GRILL vegetables on greased grill over medium-hot coals 8 to 10 minutes or until tender, turning and brushing occasionally with reserved 1/4 cup dressing.