Combine all marinade ingredients (except shrimp) in a large zip-top bag or medium bowl. Stir in shrimp and marinate in refrigerator for at least 30 minutes.
Over medium-high heat, bring ¼ cup of marinade to a boil for a minute, then add shrimp. Boil gently, uncovered, for 3 to 5 minutes or until shrimp turn opaque. To a warmed corn tortilla, add cabbage, carrot, cilantro, avocado and 4-6 shrimp. Top with extra lime juice, if desired.