While I am not sure I would expect this from a vehicle only a few years old but my (an 01) horn was doing the same thing. It seemed that I just had to hit it in the right place however the place kept moving. I checked into a new cover and for an 01 it was quite a bit more than 130 it was more like 250. In any case I didnt buy a new cover I was going to do as you suggest and just wire in another switch for it. Looked in the manual and found the color etc. I started looking for it under the steering column and what did I find but a broken wire and it was the horn wire. I guess from moving the steering wheel up and down so many times over the years. Long story short I would check for a broken wire just underneath the steering wheel were it pivots. You might get lucky and get away with a 30cent repair instead of 130. 00.