That carpet can still come cleaner. Although it looks much better.
Try some baking soda (Arm & Hammer), warm water and a stiff brush. Enough where you make a paste, like curdled milk consistency.
Work it in and let it sit for about 5 minutes.
Then use your machine to rinse it out.
I beg to differ. You can make it look even better, new. But it's just not easy and might require a bit of trial/error. It can be done though.
For instance, I've brought back carpet that was heavily matted but not worn through. I used a wire cup on my grinder to 'fluff' the carpet and that brought it back to a better than new feel. Also opened up the strands so detergent could actually get the dirt out. Granted that was a nice high pile carpet and the Focus is basically astroturf.
The thing you won't be able to do is get the carpet to fit like it's factory. It's been water damaged too much for that.
Well at least not W/O some epoxy/heat and time (to remould the backing).