A friend of mine recently bought a 00' X5. It looked to be in good shape except the headlights were cloudy. I attempted to clean them first with plastic cleaner, then polish, and finally rubbing compound, all to no avail. Upon close inspection, I saw that the lenses were actually crazed, that is, millions of hairline cracks. There would be no way anyone could rub out these cracks. If I had to guess, it looked like that X5 spent a lot of time parked in the sun.

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2013 X5 3.5i M Sport
2004 M3 cabriolet SMG