I had trouble getting that trainer to work until I right-clicked the icon and chose "Run as administrator".
But then only built-in cheats like "spawn jetpack" or "weapon tier 1-3" would work, but nothing else. And like the above user mentioned, trying to spawn any cars from the drop-down menu would result in a Dozer every time. And I have no mods whatsoever installed - using version 2.0 on Windows 7. Though I can attest that I had the same car spawning problems when I was using XP.