This is my 2nd center cap to come apart. I noticed that I lost the outer metal part on the first one 2 weeks ago. I then checked the rest and found another very loose, and when i removed it it basically came apart in my hand. It appears to be a 2 piece design that is glued together, but the glue isn't holding up. I have had my wheels for around 9 months.
Toyota is warrantying them, but I just wanted to throw this out there.