Url With + Character Page Not Found 404

Hi,

I have a url rule that adds a database field to the url. domain.com/make/id/the+is+a+car+make.

But the server returns a 404, I manually change the + to a _ and the page is found. I am assuming its to do with the url rewrite module in IIS, but not sure what I can do.

Could anyone give advice?

Thanks!