Yeah! I was on a USA holiday myself only in the last few weeks and I still have a headache from all the honking! It's very common / accepted practice there to constantly honk the horn at traffic in front of you if they are too slow or dare to make a wrong move at a junction... not good for a nervous tourist struggling with a Garmin!
Then as Jimble says, the cars have so many beeps and warning noises, they'd really do your head in. I was lucky enough to get a Ford Mustang for a few days, only had 300miles on the clock when I got it. Lovely car, but those of us used to German interior build quality would be appalled by the fit and finish in it. The ignition key was like something from a 1988 Toyota!
Here's the beast I had...
