Today while I was driving and on the phone (bluetooth), all of a sudden I heard a loud noise - I thought someone was honking at me but i realized it was my horn - it went on for about a minute or two and then stopped. I don't know if it had to do with the phone or what (the phone still works). Then, when I tried the horn, it doesn't work at all. I plan to take to dealer tomorrow because I assume it's under warranty, but also have another question. When I bought the car about 6 months ago, I found out from Mercedes (NOT from the dealer) that when the car was about a year old, the sunroof motor was replaced and the headliner removed and reinstalled. The funny thing was that at that time, the car reverted from individual ownership to the ownership of the dealer and it was used as a loaner car for the next two years before I bought it from another dealer. The dealer who owned it originally told me the sunroof motor was a warranty repair and it was necessary to remove the headliner to repair the wiring. A friend told me that airbag deployment can also damage the sunroof motor and possibly the car was in an accident but the dealer may have fixed it and then used in fleet of loaners. Is this plausible? How would someone know if the airbag ever deployed or the car was in an accident? Is that not possible to know once the airbag has been re-installed? I was thinking maybe the horn is a related problem??? Another thing is the car seems very noisy from wind/air - much more than a Mercedes should be. I can't find any air blowing in but even passengers have noticed that it feels like we're in a windstorm anytime over about 60 miles an hour. Is this normal? I appreciate any thoughts.