I wish I knew too, as my 124 has obvious sheet metal screw (or rivet) holes along each fender lip, left from the removal of the chrome trim by the previous owner (or dealer).

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car