Two problems related to wiring have been reported for the 2006 Toyota Prius. The most recently reported issues are listed below.
Headlights of 2006 Prius go on and off at will. I reported this to Toyota dealer and was told that they had to change both bulbs. The intensity of the bulbs are normal when they come back on and I have never owned a car where the bulbs recover on their own. It appears to be a wiring problem of some kind and Toyota's solution of changing the bulbs does not seem to be a reasonable solution. Also the one year guarantee of an expensive repair does not seem reasonable. The Toyota website shows hundreds of complaints for the same condition.
To date we have not had an incident, however I believe the failure of our headlight and the lack of Toyota to correctly identify and correct this problem is unacceptable. The failure occurs everyday while driving the vehicle. We were told by the dealership to replace the bulb. The cost of the repair is over $500. 00. After reading many complaints, the wiring or connection seems to be the problem, not the bulb.