The shiny aluminum door sill plates with "Model S" on them, on my brand new Model S, seem to be made to become scratched and dirty. I searched on the forum for references to sill plates, and found that one party was selling illuminated/non-illuminated sill plate overlays (which seems expensive overkill to me, and only applies to the front door sills in any case), and another poster mentioned installing some sort of 3M film product over the footwells (without specifying the exact product). Does anyone have a clean, inexpensive, practical solution to this issue for all four doors?