A note of warning to those with problems with the trainer (whose game version matches the trainer version); It's not compatible with Windows 8, unfortunately . If your running Windows 7 or earlier then look at the trainer troubleshooting guide.
I haven't seen any of these trainers that say they work with Windows 8, but they do. Except for this one, which is something with what the trainer is looking for.
GameFly version does not work with this trainer. It says it can't find the game, even though I have Tropico 4 Gold Edition w/ Modern Times and the correct version number.
I'm pretty sure that the GameFly version is considered Retail. You don't have to have the GameFly client running to run the game.