Preheat the oven to 190°C/gas mark 5. Grease 2 muffin tins.
In a large bowl combine the muffin mix, corn, garlic, and sundried tomatoes. Stir to combine.
In a small bowl whisk together the buttermilk, soured 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 about halfway. Bake until golden brown on top, about 15 minutes.