An automotive lighting appliance comprising: a substantially basin-shaped rear casing ; a front half-shell which is arranged to close the opening of the rear casing , and is provided with at least one transparent or semi-transparent portion ; and at least a first lighting assembly which emits light on command, and is located inside the rear casing so as to be able to backlight said transparent or semi-transparent portion of the front half-shell ; said lighting assembly comprising: at least one light-guide plate made of photoconductive material, which is arranged inside the rear casing with a front sidewall of the plate facing said transparent or semi-transparent portion of the front half-shell , and with a rear sidewall of the plate facing the rear casing ; and light emitting means which are located inside the rear casing at or close to the rear sidewall of the light-guide plate , and are adapted to direct the light produced inside the light-guide plate so that said light travels inside the light-guide plate towards the front sidewall of the light-guide plate and is emitted from the light-guide plate through the same front sidewall directed towards said transparent or semi-transparent portion of the front half-shell ; wherein the light-guide plate is divided into at least a first and a second plate-like sector co-planar to each other, which are arranged mutually adjacent and contiguous, are made of photoconductive materials with refractive indices different from each other, and are stably joined to each other to form a single plate-like body/piece along a join line that extends substantially from the vertex of the light-guide plate delimited by the front sidewall and by a first lateral sidewall of the light-guide plate , to an intermediate point of the rear sidewall of the light-guide plate . said lighting assembly comprising: at least one light-guide plate made of photoconductive material, which is arranged inside the rear casing with a front sidewall of the plate facing said transparent or semi-transparent portion of the front half-shell , and with a rear sidewall of the plate facing the rear casing ; and light emitting means which are located inside the rear casing at or close to the rear sidewall of the light-guide plate , and are adapted to direct the light produced inside the light-guide plate so that said light travels inside the light-guide plate towards the front sidewall of the light-guide plate and is emitted from the light-guide plate through the same front sidewall directed towards said transparent or semi-transparent portion of the front half-shell ; wherein the light-guide plate is divided into at least a first and a second plate-like sector co-planar to each other, which are arranged mutually adjacent and contiguous, are made of photoconductive materials with refractive indices different from each other, and are stably joined to each other to form a single plate-like body/piece along a join line that extends substantially from the vertex of the light-guide plate delimited by the front sidewall and by a first lateral sidewall of the light-guide plate , to an intermediate point of the rear sidewall of the light-guide plate . <EOS>