You want to hitch a trailer with a maximum authorised mass over 750 kg to your car. What must you ensure in this situation?

When hitching a trailer with a maximum authorized mass over 750 kg to your car, it is essential to ensure the following:

1. **Ball Coupling Check**: The handle of the ball coupling must be visually and mechanically checked to confirm it is secure. This is crucial for safe towing, as a loose coupling can lead to disconnection while driving, which poses a significant hazard.

2. **Breakaway Cable**: The breakaway cable should be properly fitted. This cable is a safety feature designed to activate the trailer's brakes if it becomes detached from the towing vehicle. Ensuring it is correctly secured is vital for preventing accidents.

3. **Lighting System Check**: After coupling the trailer, checking the proper functioning of the trailer’s lighting system is necessary. Working lights are essential for visibility and signaling to other drivers, thus contributing to road safety.

Each of these steps aligns with German traffic regulations, which emphasize the importance of safety checks in trailer towing to prevent accidents and ensure compliance with legal standards. Skipping any of these checks can compromise safety on the road.