Light guide for automotive use

A rear view mirror assembly for a motor vehicle, said rear view mirror assembly comprising:

• a mirror base fixedly securable to the motor vehicle;
• a mirror housing securable to said mirror base, said mirror housing including a reflective element movably secured therein;
• a light guide module fixedly secured to said mirror housing, said light guide module including a light guide having an entirely smooth and flat outer surface and a lens covering said light guide with said light guide and said lens formed integrally, said light guide defining a recess dividing said light guide into first and second portions such that a first length of said first portion is greater than two times a second length of said second portion, said recess defines a recess depth (H2) and said light guide defines a light guide thickness (H1+H2) such that said recess depth (H2) is greater than half of said light guide thickness (H1+H2);
• and a light source inserted completely into said recess such that light emitted by said light source is received and guided by said first and second portions of said light guide.