The early Alfa Romeo Duetto- my first car at 16- came fitted with nice headlight covers, but they were illegal in my state, so I had to remove them for the inspection. In the case of the Alfa, it was really designed to have them and complimented the design. The fitment was designed into the buckets, and worked well- the trim ring was removed and there were slots around the headlight and one clamp at the front. They were easily removed with one screw.
I do intend to fit them on my Europa, but I will come up with a clever attachment method.