There's a link on YouTube somewhere of a guy doing it in a lot more stages with the Griot's Garage buffer and several pads, came out looking like glass. That X5 still seems to have a faded look right around the turnsignal, and 500 grit seems pretty rough. The E90 guy used 800-1000 for the first pass and several passes with 2000-3000 grits, plus two polishes. Let me see if I can dig it up.

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8/06 build E53 3.0i....