2009 Toyota Tacoma lighting problems

My 09 toyota tacoma drl (daylight running light/turn signal) lens burned/melted/broke. I have exceeded my warranty but I feel toyota should stand behind their product and replace my light lens. My local dealer did do a 50/50 split on the cost of replacement, but this is a design problem. Light lens should never burn/melt/break regardless of how old or how many miles the vehicle has on it. Not all tacoma's have drl , this is an option, my local dealer did not know this but I pointed this out to him.

Air bag light on, toyota found DTC s b1785 occupant classification sensor front left collision detection, b1650 occupant system malfunction, zero point calibration and sensitivity check done but toyota hawaii says we need to replace front right seat sensor mat assy. Is that a safety issue and is this a manufacture defect? Took to toyota 3 times now for the same issue of the air bag light coming on. Please advise, thank you! Both lens bulbs melt inner side of plastic parts on the headlights.