Hi marky , i did notice 2 left and 2 right marked up inside them , when i cleaned them i will now check if i have the front and rear in their corect placesthey do save your sills and bear in mind that they are unique fitment, front left/right rear left/right and not interchangeable!
they are crud catchers, remove them and the plastic strips.
I'm running with mantec sill plates btw