^ I think the best thing you can do is to thoroughly clean out your tracks every few months and wipe away any grease you can and then re-lubricate lightly. A very thing coating on all the parts seems to be best. The two biggest enemies of these thing is debris getting in the track and plastic drying out. You can avoid both of those things by making an effort to maintain these things.

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2004 e53 m54 with 6spd manual