Britax Vigour

I tried Ebay, but there is nothing there

You can try Mothercare, Toys R Us stores and big baby like that even if there is an Ethel Austin near you, they mite there.

What manufactor of the stroller?
try on site.

Or what about Ebay international sites?

I do not know but you can get universal raincovers for 3 or 4 wheels, I got mine off eBay, just type in the universal rain cover.