not sure if the trainer supports the trial, the game might have a different file setup.
Because its for offline, just keep your internet unplugged buy cars upgrade them and voila you have a pimpt out garage. after you put your internet back on your money will go back to what origin has on its cloud data i guess.
trial is named something else, and there is no trainer for the trial, only the full game.
read what you just wrote. It explains why.