A side vehicle mirror assembly (30) that utilizes a waveguide (42) to route light from a location at the vehicle/mirror assembly interface to an outboard location (46) on the mirror assembly. The side mirror assembly (30) includes the waveguide (42), a mounting member (32), and a mirror (34) attached to the mounting member. The waveguide (42) extends from a first location at the vehicle/mirror assembly interface to a second location at the mirror. A lamp (44) located either in The door panel (38) or at the first location is used to provide light into the waveguide, which then routes the light to the outboard (46) location for exterior illumination or signal lighting. A stacked waveguide arrangement can be used so that these multiple lighting functions can be incorporated together into the mirror assembly. Also disclosed is an optical coupling arrangement for routing light to a breakaway side mirror.