Seal for vehicle lighting unit

The seal is made from a panel of a supple material with an aperture (12) to receive a unit. The supple material is one that forms a surface skin automatically on extrusion, and at least one edge of the seal is made with a raised lip perpendicular to its surface. The seal, designed to be fitted between an optical unit and a support in which it is inserted, is made from a panel of a supple material with an aperture (12) to receive the unit. The supple material is one that forms a surface skin automatically on extrusion, and at least one edge of the seal is made with a raised lip perpendicular to its surface. The panel, which can comprise two or more coextruded materials (P1, P2, P1) of different hardnesses, can be made in a strip that is cut into sections with apertures made at the same time.