On about 8 or 10 occasions during the 1200 miles on my '05 while driving along the horn would very briefly sound (as if you had bumped the steering wheel- which didn't happen in these cases). First time it happened, I thought might be some fancy feature serving some purpose that I hadn't learned about but the owner's manual quickly discounted that.
Maybe an intermitant short in the horn circuit? The horn pad on the steering wheel is definately not oversensitive. Anyone else experienced this?