A vehicle lamp capsule 32 having a base 34 having a spring 5 which, when lamp capsule 32 is installed, biases an inner surface of a vehicle lamp reflector 12. Spring 5 is monolithically formed with base 34 along with at least one reflector-locating structure on the base such as circumferentially extending exterior locating surface 44 and/or retaining keys 42. Base 34 and spring 5 may be molded of a plastics material. In other embodiments base 34 and spring 5 are made in one piece of sheet metal. The spring 5 formed unitary with the lamp base 34 meets regulatory requirements and avoids a risk of dislodgement of a conventional separate piece-part metal spring which could cause an electrical short when the lamp is installed in the field. The lamp capsule 32 is suitably an H13-style lamp.