I vote for buying the parts and storing them until the inevitable happens. For the window regulator, specifically, I'd buy the window clips, regulator clip(s), door panel clips, JBWeld, and zip ties (unless you've already got all those things). I personally think the best fix is to repair the OE one, with those parts, applying the JBWeld to address the design flaw.

For me, I like fixing stuff, but I don't like taking something apart to inspect, figure out what parts I need, order them, wait, try to remember whatever I did to take it apart, etc. A lot more fun and efficient if you've got the parts on the shelf and can do it all in one session.

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2001 X5 3.0i, 203k miles, AT, owned since 2014