The o-ring on the pressure regulator is the weak link. The few one worked on the filter was fine at 160-180,000 miles. I do Recommend changing the filter and regulator together unless you are only replacing the o-ring which is usually all that is needed.

At 199466 miles I'm getting some signs of weak FPR but I'm only going to change the hard flat o-ring before either the FPR or filter.

Keep your window guides lubricated. You will probably never have to replace a regulator. All four of mine are original. Takes twice as much force To open or close the window that is in need of lubrication. I had one of my Regulators pull off the bottom of the window before I started lubricating them regularly.

__________________
2011 E70 • N55 (me)
2012 E70 • N63 (wife)