Exterior lighting devices and reflectors are dirty✓Richtige Antwort
External lighting fixtures of other make of vehicles are installed on the vehicles which are out of production
In both cases.
Erklärung
Dirty lamps or reflectors cannot provide reliable visibility and signalling, so that condition prohibits operation. For a discontinued vehicle, compatible lighting units from another make may be used under the stated exception, so their presence alone is not a second violation.