Preheat the oven to 375 degrees F. Grease 2 muffin tins.
In a large bowl combine the muffin mix, corn, garlic, and sun-dried tomatoes. Stir to combine. In a small bowl whisk together the buttermilk, sour cream, and eggs until well blended. Add the buttermilk mixture to the muffin mix. Stir to combine. Spoon the mix into the muffin tins, filling up the cups about halfway. Bake until golden brown on top, about 15 minutes.