Ive replaced my passenger side low beam 3 times in a month on my 2000 WS6. Has anyone has this issue and know what causes it? I ran a new wire(power) for the headlight(about 3 ft back in harness) because they have an issue with corrosion. I just wonder what could cause this.

 

Check for leaks/cracks.... I bet their is moisture getting in, and this is causing the bulb to blow.

 

How is your battery, lower voltage can causes thigs to run at higher amperage, similar to how the corrosion can add ressitance to the circuit... same result bulb burns hotter and doesnt last as long.