[dadvanlife]

Every time I open the lift gate I hear a rattle inside the interior trim piece on the right side. It sounds like something came loose and rattling around but only when I open the lift gate. Any one else? How easy is to remove the interior plastic trim piece (the large one that covers the subwoofer)?

 

[Dimitrij]

Every time I open the lift gate I hear a rattle inside the interior trim piece on the right side. It sounds like something came loose and rattling around but only when I open the lift gate. Any one else? How easy is to remove the interior plastic trim piece (the large one that covers the subwoofer)?

I suspect that there is a lot more structural plastic in the liftgate than it's apparent.

Occasionally, when the liftgate is nearing the topmost position I can hear a screeching sound. I thought that it was coming from the left hinge, but I will investigate a little further.

 

[Chubbysumo]

Its mostly plastic push pins(commonly called Christmas trees because they look like fir trees). There are 2 access ports that come down easy for the gate trim, they are directly on the other side of the gate maker lights. They pop right out, and then its a lot of open space, and you should be able to at least see to the bottom of the gate with a mirror on a stick. There are some bolts for the grab handle and a few others, but the tailgate itself is like 90% plastic. Hit the outside of it gently, its plastic. It has a "frame" that is bent/cut sheet metal, but the outer skin, inner skin, and about 90% of the rest of the tailgate is plastic.

 

[dadvanlife]

That’s what it sounds like. Possibly a push pin. I tried to stick my hand into the opening you’re referring to but it’s too tight for me to get to the bottom. I’m thinking of sticking my dry/wet vac down their with the hose and hopefully scoop it up that way. Hopefully I don’t suction anything else accidentally.

 

[Chubbysumo]

If the vehicle still under warranty, just have a dealership address it. That sounds like a manufacturing defect to me.

 

[Therbi]

His sig says 2022 Sienna so yes, should definitely be under warranty.
I would be willing to bet when they installed the hatch garnish they knocked one of the clips off the garnish and just didnt realize it.
Yes, you can take it to the dealer and get them to pull the garnish and fix it, or you can do it yourself.
Personally I hate dealers and find they butcher stuff bad when it comes to panel removal so I would do it myself but if you're not comfortable doing it, then the dealer is the way to go.
Have a look at this video around the 5:45 mark and you can see the garnish coming off and the white clips that hold it in place. Yes, its gen 3, but it gives you an idea of how they come off. You may actually have to remove the left and right trim pieces first before removing the larger lower one depending on overlap of a gen 4, but it wont be hugely different.
And yes, possibly some bolts holding the handles as well.
There should be nothing structural about the garnish at all, its basically just cosmetic cover up.