SL320: The stainless steel radiator grille on my SL 320 (1999) The stainless steel radiator grille on my SL 320 (W129) is badly watermarked. It doesn't sound much but does look horrible. I have tried everything from stainless steel cleaner, lemon juice and vinegar to Autosol, kettle descaler, silver polish and T-cut. Nothing works. I can't be the only owner who has had this problem, does anyone have any suggestions.