Activating this trainer:
Press F1 at main menu.
Listen for 'Trainer Activated'.
Press desired hotkey. All hotkeys can be changed on the trainer.
NumPad1: Change Gold By 500
NumPad2: Change Cash By 500
NumPad3: Infinite Fuel
NumPad4: Infinite Health
NumPad5: Unlock All Missions
NumPad6: Unlock Next Mission
NumPad7: Infinite Mission Time
NumPad8: Instant Repair
NumPad9: Skip Current Mission Objective
NumPad0: Toggle HUD
NumPad/: No Clip / Fly Mode
Gold / Cash: While its visible on the screen press hotkey to add more.
Infinite Fuel: While active all objectives that needs fuel have it unlimited.
Unlock All Missions / Unlock Next Mission: Press hotkey to unlock all missions / next mission in mission menu.
Infinite Mission Time: While active if a mission has a limited time, it's unlimited.
Instant Repair: While active all objectives on the work table are instantly repaired.
Skip Current Mission Objective: Press hotkey to skip the current mission objective.
Toggle HUD: Press hotkey to show/hide the HUD.
No Clip / Fly Mode: While active you can fly around and through all objectives. Holding down SHIFT key will drastically increase your flying speed.
Unlock more trainer options including updates from here - Gold Rush: The Game Trainer