Unfortunately 3 weeks ago when I got my new 350Z it had already been sitting on the lot for about 5 months supposedly (according to the dealer)neither black nor base Z's sell well . The dealer was cool about it an even took a $100 of the price and gave me a free t-shirt and hat. It really wasn't a big deal I was able to get it all cleaned up with some polish and wax. However the windows had some nagging water spots (from rain I assume) that wouldn't go away. So I ordered Griots Window Polish (not to be confused with the lighter less abrasive Griots fine window polish). This stuff is absooutely amazing. Not only did it get all the water spots off, but I've never had car windows so clean. I give this stuff a 10/10. It's really a must for anyone who has trouble with dirty windows.