Which model and year are you driving? E32 or E38? Do you have self levelling with EDC or without? If EDC, which type? EDC I, II or III?
Self levelling shocks last at least 100k miles and they are worth to be replaced.
Why do you think they are to be replaced? Leaking? If not, what is the problem?
Please fill out your profile more in detail, otherwise one cannot really help.
And where do you live? Europe, USA, Asia, Oceania?
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http://www.autohausaz.com/