A lot of times if the seal around the light is broken in any way it can let condensation or any other forms of moisture. Basically this will build up over time and destroy bulbs. Not much you can do about it other then replace the housing.
2004 Focus PZEV 2.3L - KW sport suspension, SP camber plates, Eibach front swaybar, FS intake, FS Stealth exhaust, 3.82 Final, Torsen ATB, Prothane MM insert, E1 CSVT wheels
1/4 mile - 15.201@89.4mph
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