One problem related to carrier/rack has been reported for the 2009 Toyota Prius. The most recently reported issues are listed below.
If my car sits in the sun, on occasion the audio controls - am/fm, volume, power, track selector, etc. Fail to function (they are unresponsive). If the car is turned off, then back on, they work. This is not a safety concern, per se. My concern is not the audio portion not working, but the system design and quality of components. Were these same components used elsewhere in the car? I've only seen this happen when my car has become hot sitting (not running) due to the weather. Usually when I parked facing west and the sun has been hitting the front of the car all day and I leave from work. This hasn't happened in the past 2-3 years because I've kept my car out of the sun when parking. It occurred between 2012 an 2014. I do not have an exact date of when it occurred even though your form forces me to specify one.