I, too, used to live in South Florida and am a Pollo Tropical addict. I even called the company while I was living in Canada to ask about how to make it and was told that it is SO secret that one provider for the company makes the fruit juice marinade and another makes the spice mixture, which leads me to believe that the recipe listed above is a touch simplistic to duplicate Pollo Tropical, although I have made the same chicken myself plenty of times and it is amazing. I would suggest the following additions to the recipe listed above, which included garlic, sour orange (or orange and lime combined) juices, cumin and salt and pepper:

1 teaspoon dried oregano leaves
1 tablespoon fresh minced cilantro leaves
1/2 cup pineapple juice
1 small minced jalapeno pepper, seeds removed

The other amazing dish from Pollo Tropical is their Fried Pork Chunks, which I have never even tried to duplicate. If someone has more insight to ANYTHING from the chain, I am happy to listen!