I've heard of the horn not sounding over 25mph, and it looks to me as though it is true. I bought a '04 TB on Oct 12th, and a woman pulled out in front of me on the 16th as I was exiting off an interstate and I couldn't get out of the way fast enough. I tried the horn, but never heard it. As I hit her going 65 mph, I thought it was kind of strange that the airbags didn't deploy when the force was enough to rip off my right front suspension. After coming to a fairly abrupt halt (considering my hand slapped it into park going 65 mph) I tried contacting Onstar. I then tried again, and again, and again. Well, needless to say, it didn't work either. Has anyone else seen any of these problems??? Needless to say, I really hope there's enough damage to total it. Don't feel too safe driving it anymore.

you probably didn't impact the immeadiate area of the airbag sensor(s) well enough to trigger them.