1. Combine vinegar and sugar in medium bowl. Place shaved carrots, sliced cucumber and cilantro in the vinegar mixture to marinate.
2. Heat charcoal or gas grill to about 400°F. Grill pork tenderloin 18 to 30 minutes until internal temperature reaches 150°F. Let stand 10 minutes before thinly slicing.
3. Slice baguettes horizontally, leaving one long side attached like hot dog bun; lightly toast on grill for 2 to 3 minutes. Combine mayonnaise and sriracha sauce in small bowl.
4. Spread mayonnaise mixture on both sides of toasted bread. Layer thinly sliced tenderloin in baguettes. Top with pickled carrots and cucumbers.
5. Cut each sandwich in half for entrée sandwiches or into quarters for snack size.