When must attachments have additional lighting systems?

You answered correctly. Attachments on vehicles must have additional lighting systems in three cases: when the attachment blocks the vehicle's existing lighting system, when it extends more than 40 centimeters beyond the side of the vehicle in relation to the front or rear position lamps, and when it sticks out by more than 1 meter beyond the rear retro-reflectors. These rules ensure that all parts of the vehicle and its attachments are clearly visible to other road users, especially at night or in poor visibility, which increases safety. Always remember to check attachments for these situations before driving.