2018 GMC SIERRA 1500 Exterior Lighting Problems

The left rear tail light assembly is subject to direct wheel spray resulting in premature corrosion and failure of the lightbulb and wiring harness. Failure first occurred Within 18 months of ownership. I cleaned the contacts and packed the connection with dielectric grease. However after three years the bulb connection is now totally corroded and the circuit has failed requiring harness replacement. The problem is so widespread, replacement wiring harnesses for the left rear tail light assembly are out of stock and unavailable from GM parts. I am now using the vehicle without operating right rear turn signals. GM-trucks.com is an owners chat room with many entries about this problem. [XXX], BSME, P.E. SAE INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).

PASSENGER SIDE HEADLIGHT JIGGLES UP AND DOWN CONSTANTLY OVER EVERY SMALL BUMP. VERY DISTRACTING AND LEAVES MANY BLACK AREAS ON THE ROAD FROM LACK OF LIGHT. FIX THIS IMMEDIATELY!

PASSENGERS SIDE LOW BEAM JIGGLES UP AND DOWN WHEN GOING OVER SMALL BUMPS. DEALER TELLS ME ITS A COMMON ISSUE WITH THE PROJECTOR STYLE HEADLIGHTS BUT CANNOT BE REPLACED UNDER WARRANTY UNTIL GM RECOGNIZES IT.