Rear reflectors

[Quiny]

As my pile of parts grows smaller I see two rectangular red reflectors, I assume they are for the rear. Is there a requirement for them? I have noticed that all modern cars have some sort of wrap around taillight.

[Bob_n_Cincy]

There is a requirement in some states that you have side reflectors front and rear. They are typically built into the head and tail light assemblies. Since the 818 rear taillights can't be seen from the sides. the reflectors are required.
You can see them on this corvette.

11229c6_cutaway.jpg