hi there i have amk5rs2000 and im responding 2 the pics of the black mk5rs with the rotten floor,i had almost identical trouble with mine,i had to by two sills for both sides of my rs and cut the lip off one of the sills ,n weld that 2 the floorpan to create a sill lip for the other sill to be drilled and welded to its amazeing wat u find under plaggy side skirts,u never mentioned your chassis rails,again these had seen better days on my car,thankfully tho for me i have a good mate whos a genius when it comes to metal fabrication. hope u get your car sorted.