TL;DR: A hard sustained press to the center of the steering wheel should honk the horn. I have a 2016 Model S 70D and last week there was heavy rain in Seattle where I almost got in to 2 accidents. The first one, a driver just decided to hop across lanes of traffic while I was stopped at a light, almost hitting me and a few other cars. The second time, the rain was so heavy that autopilot got the lanes on 99 South wrong and tried to leap over to the left where the lanes used to be many years ago. I took over but autopilot never warned me of a problem nor did it detect the large silver SUV I almost hit. I tried to honk in both situations, but the steering wheel does nothing if you press the center or anywhere other than a very targeted press with fingers on the horn icons. I can't imagine in a situation where you actually need the horn being able to look down to make that precise of a motion while still trying to avoid a collision. By the time I got the horn to honk, the danger was over and I was laughing about how hard it is to honk the horn. So hard to honk consistently that I thought it wasn't possible or that my hardware was broken. Accident was avoided in both cases, the second time because the other driver swerved and honked at me. The entire reason I bought a Tesla was for safety. I love many aspects of it, but why is the horn so small? Is there some option where I can customize this?