Preheat a stove top or outdoor grill to medium high heat. Place corn on hot grill and cook until kernels are tender and lightly charred, about 2-3 minutes per side.
In a medium bowl, whisk to combine mayonnaise, sour cream, thai sweet chili sauce, fish sauce, sriracha and 1 tablespoon lime juice. In a shallow bowl or pie plate, combine the toasted coconut, peanuts, salt and 1/2 cup chopped cilantro leaves.
Transfer corn to the bowl with mayonnaise and sour cream mixture and spoon to coat completely. Place corn over plate with coconut, peanut and cilantro mixture and spoon or sprinkle over to coat on all sides.
Transfer corn to a serving plate and garnish with lime wedges and a drizzle of Thai sweet chili sauce and cilantro springs.