The plastic clips that hold the window to the regulator are about $1.50 each at a dealer. They are available for more bucks on Amazon, too. They have a special nut that slips inside, and a bolt. I found those on my X at the bottom of the door cavity. I would get the window properly secured before doing any more troubleshooting. The zip ties will let it wiggle around and I think it would have a greater chance of getting jammed.

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David.X5
2001 X5 4.4i Sport
SOLD! at 160k miles