I recently brought my 2011 in for its final warranty service with a laundry list of issues, one of which was the tailgate panel that was always loose and rattling. Of course the dealer told me there was no problem, and it's always been difficult to isolate the source of rattles on this car since the entire car is a symphony of rattling plastic. As usual with warranty; the dealer was unable to validate this or any of my other contentions. I looked into the tailgate panel more closely to find that the two plastic grab handles built into the tailgate panel were loose. I pulled the panel off to discover the root for the problem. The two plastic grab handles are sonically welded (melted) to the tailgate panel, (five welds per handle). Three of the five welds on each handle were fractured, (six out of ten welds had failed). I took the panel back to the dealership and showed it to the service manager who miraculously concluded that the panel was defective, but it wasn't like that when they looked at it the day before (right!). Of course the dealer was pleased to bang Toyota for $110 in labor on a warranty claim for me to remove and replace the panel. I'm sharing this story because I'm quite certain that Toyota wasn't just picking on me; I'm confident that lots of other folks on this forum have the same problem and once the car runs out of warranty, you will be the owner of the $250+ parts and labor repair. Check yours out today! I've attached a photo of the two handles from the backside of the panel with a close-up of what the failed welds look like.
I recently had that panel off for a mod I did and also discovered some loose "welds". I had an old soldering gun so I just "re-melted" the bad welds and it was firm again. I make a point not to use those grab handles when I close my hatch.
Amazing that the dealers do the whole: "This is normal", "Nothing is wrong" routine and then expect you to return there for service.
Whether it's poor quality plastic or improper production process, the point is to check your car and get Toyota to pay to fix their problem before it turns into only your problem. How crazy is it that you need to avoid using the grab handles for their intended purpose to ensure they don't fall apart? The welds failed on both handles on my car, yet I've only used the one on the passenger side because I'm right handed. This indicates to me that the failure is not a consequence of use, but of poor design/build quality.
I had a similar type weld fail on my driver's door panel, where the cloth arm rest assembly attaches to the plastic interior door panel. I took it to the dealer under warranty and the Service Advisor first tried sending the panel to an auto interior shop to have the welds redone. This lasted about 2-3 months and they failed again. The second time the Service Advisor finally replaced the interior door panel and I have not had any further problems.
