After 2 weeks with a new 2008 Civic, I heard a horrendous scraping while driving. Had it towed to the dealer, and the next day the service dept. called saying that I had bent the backing plate and must have hit a curb. In the 2 weeks I had the car, I ran over no curbs, no potholes, no small animals, no pedestrians. Is it possible that the backing plate was bent prior to purchase and just didn’t show itself until 2 weeks later?
If you said a light scraping noise intermittently detectable, I would say maybe but not probable. A ‘horrendous noise’ would be expected to make its horrendous sound all the time. That wouldn’t take 2 weeks. Those backing plates are usually quite thin and easily bent. Running over a branch or something fairly insignificant could do that. I wouldn’t think about it too much, and just enjoy your most excellent gas milage!