Mix margarita mix, lime juice and garlic in resealable heavy-duty plastic
food-storage bag. Add chicken; seal bag and turn to coat with marinade. Refrigerate,
turning bag occasionally, at least 1 hour but no longer than 24 hours.
Remove chicken from marinade; reserve marinade. Heat coals or gas grill.
Place chicken, skin sides up, on grill. Brush with marinade; sprinkle with
1/2 teaspoon of the salt. Cover and grill 5 to 6 inches from medium heat 15
minutes; turn chicken. Brush with remaining marinade; sprinkle with remaining
1/2 tea-spoon salt.
Cover and grill 20 to 40 minutes longer, turning occasionally, until juice
of chicken is no longer pink when centers of thickest pieces are cut.