I prefer removing the hood liner to wash it down and for quicker dry time. As an expert detailer I prefer to protect and restore the refinished metal and rubber with 3M brand Pure Silicon Spray. $12.00 a can but It does not have any of the damaging and greasy petroleum distillates found in the cheaper silicon sprays. Spray it on, let it set, wipe it down. It will not turn white as other white detailing creams will. Plus it prevents rusting and pitting while keeping rubber from drying out.