Yup, it happened backing out of the garage. Anyway, we got it fixed, but the NEW mirror shakes badly as I drive down the road. When looking through it to watch the trailor being pulled it gives me a headache. I went back to the dealer that replaced it....the tech said there's nothing he could do. What's up. Is there something he could tighten, or is he just fudging cuz he would have to replace the new one due to being defective? This is an '04 duramax with the accordion-like extending mirrors.