This is the BMW rear shock mount used on 1997-2003 E39 525i/528i/530i and 540i (non-M Sport 2) models. BMW calls it a Guide Support and it mounts the top of the rear shock absorber to the chassis. Rear shock mounts are a normal wear item and should be replaced with the shocks or sometimes on their own if there are any clunking sounds or thuds coming from the rear suspension. Too much play in the rubber mount can also cause shock absorbers to fail early.
Fitment Note: The E39 540i “M Sport” models sometimes came with different rear shocks and different rear shock mounts. This is especially true if your 540i has the “M Sport2” suspension (modeled after the M5). This particular mount may fit 540i M Sport, but may NOT 540i M Sport 2 equipped models. We recommend checking your current part or part number if you are not sure.
This is an OEM E39 rear shock mount manufactured by Sachs-Boge - the original supplier to BMW for this part, as well as many rubber mounts and bushings. As the OEM it meets all of BMW's original design, fitment, and performance requirements and is TUV approved. OEM parts are the best alternative to more expensive Original BMW parts because they are virtually identical without the inflated price tag. This part has a two year warranty.
E39 (97-03) > 525i
E39 (97-03) > 528i 97-98
E39 (97-03) > 528i 99-00
E39 (97-03) > 530i
E39 (97-03) > 540i