I have silver X5, living in southern California, I can easily go 2 weeks without washing. Black color is the right color for any car period. (Maintenance, maintenance, maintenance...) If I had my choice I would consider estorill blue. I think that will be unmisteakable 4.6 color. (you can get silver or black 3.0 or 4.4, but neither in estorill blue....) Carl