Hello, I have a detailing question.. I have a almost new Z4, and the only cosmetic thing wrong that bothers me is the instrument cluster, the clear plastic has a water stain. I researched that that the clear plastic is not interchangeable, I will need to buy the whole cluster unit... I tried cleaning with a micro fiber damp rag, but did not clean it off. Is there a product that will target this stain, that is not abrasive? I thought the stain was from the inside, but the dealer insists its on the outside... I appreciate any feedback...