1. Peel shrimp, leaving tails on; devein, if desired. Combine shrimp and Mojo de Ajo, tossing to coat. Let stand 30 minutes.
2. Meanwhile, soak wooden skewers in water 30 minutes.
3. Remove shrimp from Mojo de Ajo, discarding marinade. Thread 1 shrimp onto each skewer.
4. Grill, covered with grill lid, over medium-high heat 1 to 2 minutes on each side or just until shrimp turn pink. Garnish, if desired.