The sport fog lamps will not fit your application if you do not have the sport style front bumper. As someone suggested above that a good look at the wiring harness & connector for the fog lamp. They can/will get weak over time causing all sorts of headaches. If you are really handy install an inline fuse in each wire of the fog lamp harness leading to the bulb. Then once the bulb stops working, see which fuse went bad and trace it from there. Now if your issues are with either bulb randomly going bad then it is a given the harness needs a deeper evaluation/repair/replacement

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2001 E55

2001 E320 Sedan

2001 Subaru Legacy

2006 SLK280

2016 Subaru Outback 3.6