What is important with regard to the official registration plates?

Your answer correctly identified all essential requirements regarding official registration plates based on German traffic regulations.

Firstly, securely attaching the plates ensures they do not fall off while driving, which is crucial for safety and legality. Secondly, their legibility allows law enforcement and other road users to clearly see the vehicle's identification, aiding in identification and accountability. Lastly, the requirement for rear registration plates to be illuminated in darkness is vital for visibility, allowing other drivers to read the plate even in low-light conditions.

Each of these elements contributes to overall road safety and compliance with traffic laws in Germany. Understanding and adhering to these rules is crucial for any vehicle owner.