Two problems related to horn assembly have been reported for the 2007 Toyota Prius. The most recently reported issues are listed below.
My car has a clunking/rattle sound when going over bumps or uneven roads even without brakes slightly engaged. It also does this when driving over 60 mph on smooth roads but if I turn wheels slightly left or right the sound stops and when I turn them back straight it begins again. It is so bad that you can feel it on your feet and strongly thru the steering colum. Also the front tires wear heavily on the inside edge. It feels like steering column may be loose at times. Also the horn keeps blowing fuses and when you put a new fuse in the drivers side door will shock you e every time you try to exit the vehicle. And the outside air temp will not read temp. I had new tires put on to replace old front tires and rotated all and balanced and just had new brakes put on from dealship. Radio reception is horrible even though other vehicles in same area get great reception. I love this car but I did buy it used so I am not sure if all recalls have been fixed or if they need fixed again. It seems like a lot of mechanics have no idea what they are doing.
I have seen the recent recall related to many makes and models of Toyota's for the clock-springs or spiral cables in the steering wheel. This is a very important part of the car which provides the electrical connection for many components such as the steering wheel controls, horn, and air bags. I have heard of others with the same issues in their generation ii Prius (2004-2009). My spiral cable has recently stopped working as well and seeing as this is a safety issue I believe Toyota should be responsible for correcting it.