Here's our 2009 with the plastic sill cover removed. About what I expected to be honest. Will be getting a quote from the local spray shop to repair... N/S as shown is the worst of it. Rust never sleeps....

Came over all tight and decided to have a go myself. Sill was filled with waxoyl. Zinc primer for now, top coat to follow.

Just an aside to all these problems with rust forming at the rear of the cills behind the covers.
Having had the cill covers off last year and luckily found no rust what I did find was a lot of wet dirt. To me it seems water and dirt is getting through the joint between the rear return of the plastic cill cover and the wheel arch liner and draining down to the bottom of the cill cover where it sits and causes corrosion.
To overcome this I cleaned up the rear return of the cill cover and the wheel arch liner and taped up the joint with black Gorilla tape. Once applied you can't see it and after over a year it is still in place.
Might be worth considering.

That's a top tip fella. Will give it a go. Thanks. Perfect night for spray painting here, zero wind, so just been out and flashed over the primer with top coat, just before bad light stops play....

I think I will try the Gorilla tape tip. I have gotten quite good at removing the plastic sills, however not so good at lining up those clips and retrieving them when they fall in the sill

Ordered a pair of Freelander 2 wheel arch protectors as suggested somewhere on here, thanks.

https://rimmerbros.com/Item--i-LR001624

Cill is looking much better. Glad I got some top coat on last night as rain stops play today....

Now you're just showing me up! Can I buy it back?

Nice job - looks really great. 2016 Skoda Octavia VRS Estate
<gone>2009 FF Vogue TDV8 Buckingham Blue</gone>
<gone>2015 BMW 520D SE (not my favourite car)</gone>
<gone>2009 D3 HSE Galway Green</gone>

Had my long waited appointment at a local blasting shop. They did cleaning of the rust at the whole
underbody. Next stop is welding and then the paint shop! Car is 2006.

WOW That is some protection job