Wiring problems of the 2008 Toyota Prius

Multiple occurrences over the past 3 years of headlights (one or at times both) going out unexpectedly without warning. You go into partial lighting or total darkness. After a few minutes you can turn the headlights back on and they may stay lit for few minutes or several hours. I have had dealerships look at the car and say that it is just the bulbs failing (bulbs that are suppose to last 10 times longer than conventional bulbs). The car is now 4 years old and I have had to replace the bulbs yearly. Dealership costs that was originally $350 plus installation per bulb. Toyota has now dropped their price to $150 per bulb. Aftermarket bulbs now available but you still only get a life of 7 months to a year per bulb lots of talk from dealers but no solution. I went to after market bulbs thinking that the problem was Toyota bulbs. The same problem occurs. The problem is not the bulbs, the problem is in the vehicle wiring. This is a severe problem that must be looked into in that it putting a lot of Prius owners along with others on the highway at risk.

2008 Toyota Prius (touring model) -- driver side hid headlight began to fail in sept 2009. Became more frequent as time elapsed (would occur 3+ times during 30 minute trip). Turning lights off and back on temporarily resolved issue, but driver bulb would eventually fail again. Resulted in reduced visibility and potential blind spot for driver in front of vehicle. Researched online - suspected ecu. Contacted Toyota corporate around December 2009. Was advised that ecu was not the problem - bulb repair suggested. Dealer diagnostic suggested. Did not go to deal to spend $100 to tell me a light bulb should be replaced. Received notice Jan 2010 that symptoms matching mine was due to headlight reaching end of life. Ordered and attempted to replace bulbs in Jan 2010. Did not bring to Toyota as cost to replace bulbs was at least 6x more that "do it yourself". Attempt to replace bulbs resulted in mixed success. Was able to get both hid headlights replaced and functioning (after passenger side or driver side would not remain on consistently). Tested high beams - after high beams were disengaged both headlights went out, but headlight switch remained engaged. Disconnected and reconnected wiring. Only passenger side bulb functioned. Afraid to use high beams and no faith in headlights. Reluctant to spend hundreds of dollars to have dealer change bulbs, same problem occur, and spend hundreds or 1,000+ dollars. Original bulbs retained and I will be putting them back in once weather is warmer. Strong belief that bulbs are not to blame and ecu or other electrical component is at fault. Dozens of similar issues reported online.