Fog Lights problems of the 2004 Toyota Highlander

I have a 2004 Toyota highland and believe there is a design defect or manufacturing flaw with regard to the lens covers to the headlights and fog light covers. Both have significant melting from the light bulbs. I am concerned that the vehicle will catch on fire. All products involved are original Toyota parts. The lens covers each have a large (bigger than a quarter) circular spot where the melting took place from the inside out and there is a bubble on each. The same has happened with the fog lights and they are now cracked from the heat. I have contacted Toyota and they will not fix, replace, repair the lens covers and say that there is no recall. I would imagine that anything melting on a vehicle has the potential to catch fire. This has been progressively getting worse over several years so the incident date is not exact. It is evident that eventually there will be holes in these covers from the heat/melting as the daylights run constantly and cannot be turned off.