A method of manufacture of an automotive light comprising the steps of: - providing a container body delimited by a first perimetral profile, - providing a lenticular body delimited by a second perimetral profile, associating at least partially with each other the respective first and second perimetral profiles (20,28) of the container body and the lenticular body, the contact surface between said perimetral profiles defining a welding interface, - providing at least one laser emission device emitting a light beam or radiation having a characteristic emission spectrum, - wherein the emission device is operatively connected to a first light guide of the emitted light radiation, - providing a second light guide inside the lenticular body adapted to obtaining a light guide of the light radiation inside the lenticular body, - suitably arranging with each other the first and the second light guide (52,64) so as to route at least a first lobe or portion of the laser radiation coming from the output of the first light guide towards the second light guide of the lenticular body, so as to propagate at least one portion or lobe of the laser radiation (Li) inside the second light guide towards the welding interface, - wherein the container body acts as an absorbing member in relation to the light beam and the lenticular body acts as a transmissive member of the light beam characterised in that: said first light guide comprises an input and an output of the light radiation, so as to distribute the radiation from that output according to a spatial distribution comprising a plurality of portions or lobes (Li), - wherein the second light guide is provided with walls capable of satisfying the overall internal reflection condition for at least one portion of the laser radiation defined by at least one first lobe or portion (Li). - providing a container body delimited by a first perimetral profile, - providing a lenticular body delimited by a second perimetral profile, associating at least partially with each other the respective first and second perimetral profiles (20,28) of the container body and the lenticular body, the contact surface between said perimetral profiles defining a welding interface, - providing at least one laser emission device emitting a light beam or radiation having a characteristic emission spectrum, - wherein the emission device is operatively connected to a first light guide of the emitted light radiation, - providing a second light guide inside the lenticular body adapted to obtaining a light guide of the light radiation inside the lenticular body, - suitably arranging with each other the first and the second light guide (52,64) so as to route at least a first lobe or portion of the laser radiation coming from the output of the first light guide towards the second light guide of the lenticular body, so as to propagate at least one portion or lobe of the laser radiation (Li) inside the second light guide towards the welding interface, - wherein the container body acts as an absorbing member in relation to the light beam and the lenticular body acts as a transmissive member of the light beam characterised in that: said first light guide comprises an input and an output of the light radiation, so as to distribute the radiation from that output according to a spatial distribution comprising a plurality of portions or lobes (Li), - wherein the second light guide is provided with walls capable of satisfying the overall internal reflection condition for at least one portion of the laser radiation defined by at least one first lobe or portion (Li).