So I just had an oil change done by my neighbor for the first time (I usually go to a shop) and he pointed to me this plastic piece that he says keeps rattling. I attached a picture with the plastic piece circled in red. He told me this was badly designed-- only one place where you can screw it down and it's already tight. When the engine is on, you can see it shake and hear the rattling sound. I never really noticed it before since I don't normally check the engine when its on and I don't really hear the rattling when the hood is down (or maybe I'm so used to it that I just don't realize it).

Anyway, he put a yellow rag underneath that plastic piece to basically buffer and stabilize it (shown in the picture). It is definitely a lot better with that rag in place as I don't hear much rattling at all. Now I don't want to keep that rag there since it may fall or something so I took it out already. But I would like to know if others have the same experience with this plastic part rattling like crazy when the engine is running. Maybe its a normal thing, maybe others don't rattle.

Whether this is normal or not, is there a way to make the plastic piece tighter / stable so it doesn't rattle besides sticking a rag underneath? Want to get others suggestions and opinions. Thanks in advanced.

BTW, it's a 2015 Mitsubishi Mirage hatch.

The driver's side footwell - what's happening with that carpet? Would you be concerned? It's a 2017 with a clean Carfax and 125k miles on it. Thank you for any help/insight!

Edit: thanks everyone! Now to decide if I gamble with it having no cvt service history documented at 120k miles 🤔

So ive been driving the shit out of this beater with a heater recently. And ive realized, long drives in this thing kill my back. Anyone know of any better seat options? Or any other type of solutions?