Rear taillight bulb blows out as if an electrical short in wiring. bulb will look black, even the socket has black discoloration. this has been an on-going problem since we purchased car in 2009 with both the left and right rear tail lights. to date i have replaced about 15-20 bulbs to the extent i purchased two (2) boxes of bulbs a socket wrench and correct socket to keep in car to replace bulbs each time it happens.