Well mine has started to sag (too loose). Is Acura replacing these under warranty because it is a safety item?

 

I got mine changed, but my car was still under 50K. But you never know, sounds like it should be a safety issue. Call them up.

 

i bought one off ebay and replaced it myself, it was under $40 (same mirror as MDX) and only took about 5 minutes. Mine was so loose that when i went over any kind of bump, the mirror would go down and i'd be looking at the back seat.

 

Do a search on the TL forum...I got a free replacement because my liquid in the mirror broke...or something.