What is the name of the textured part that runs along underneath the doors of the Seat Leon MK4?

[NWkodak]

I've scraped a high kerb and almost annihilated that bit. Wondering what it would be called to see if I can fix it myself. There's no damage on the door itself. Thanks

 

[SRGTD]

If you’re meaning the panel circled in red in the picture below, it’s the sill.