Water marks on the chrome annoys the shit out of me. I haven’t washed mine in over a week due to rain and being at work and the
mirror covers have marks all over them from rain water. If you use a chamois or some other drying cloth to dry after you wash the car, give the
mirror covers and grille a run over with a microfiber cloth afterwards, they should come up nicely. Also I bought some Bowden’s Own Naked Glass cleaner for my windows, and applied it to the chrome sections as per the label and they’re like mirrors. It took a lot longer for the rain water to leave marks after using Naked Glass on them. You could also try Bowden’s Own Fully Slick which I still haven’t used but a mate raves about it. It adds an extra hydrophobic layer above your paint protection.