I am swedish and know the language well. I read the original article in Swedish from a swedish news website. It was an interview mainly about Race Pro for eXbox360, but also some other blurbs.
idg.se: "Do you have other games lined up? You always make a row of PC games each year."
SimBin: "We have a new WTCC-game lined up, for this year's season. It is built on our old game engine. This year's news is that we have a little bit more american circuits and a little bit american muscle cars. This was a request from our american publisher, so it's a bit of a flirt with that market. But USA is difficult, it is hard to sell racing games unless they are driven on cicuits that just go around, around, around."
They are probably talking about the WTCC - The game series. I.e. Race 07 was a WTCC game. Just when talking to this paper, to make it easier for them to understand. I don't think it means it will be a WTCC license.
The muscle cars and tracks does not mean some american muscle car series either. Remember that Nordschleife + muscle cars was already put into GTR Evolution. It's probably just a bit extra stuff on the side (a few more road cars and circuits unattached to any series).