The edges of the door panel that this trim goes into need to be pushed in behind the flanges of black base at the top and bottom that this trim piece snaps into. If not, the door panel material is in the way and will not allow the trim piece prongs snap into place against the attachment points. Use the plastic equivalent of a putty knife to carefully push the edges until they are behind the flanges.

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03 CLK430 Cabrio 211K Pweter Silver/ Oyster Leather
90 300SEL 214k Pearl Black/ Alto Grey/Black Leather

Prior: 85 190E, 88 300TE, 89 300TE, 90 300E 2.6, 90 300TE, 92 300E 2.6, 91 and 93 300SL, 87 Ferrari Mondial Cabrio