My Yaris Only needed one bulb in 14 years. My Corsa blew one or other of the headlight bulbs annually or 18 months on average. The make or quality of the bulb made no difference. Standard bulbs, not extra high power ones which can burn out even faster. I changed them myself, and avoided touching the glass. They say that even with clean fingers the small amount of body grease in finger prints can cause early failure.