Marks on a showerproof coat?

[BitchyInnerMonologue]

I have a long cream trench coat - which is showerproof (not completely waterproof).

Unfortunately, I leant over the boot of my car, and now have a couple of marks.

I've washed it with rewaterproofing stuff that I use for my wet gear, but the marks are still there.

What can I use to clear the marks off so that I don't lose the waterproof coating?

Hopeful bump?

Final, desperate bump. Don't want to ditch my lovely coat, but it looks manky!

Could you wash it as normal, or a patch, then re-waterproof it?

I guess that's what I'm asking! On a "normal" piece of clothing, I'd attack it with Vanish and job done.

I don't know if I can do that with this?