I believe I had some really tough rubber like roofing material. It worked perfectly. I like using rubber in such a fix because I can twice the screws while the rubber squeezes to get the right depth perfectly.

I did both sides right away as it's a straight up design defect they will all fail.

I checked mine but due to an accident my 2001 has lamp assemblies from 2009. They are a slightly different design which allowed me to rewire to use both brake filaments for full brightness

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