I'm taking a guess that it won't be out until May.
Their website isn't updated, Nothing on Facebook or Twitter, or how it will be distributed, cost, etc.
In the meantime, I look forward to Thursday when the Retro Pack released.
They said that they release game in April. But everyone knows that ISI was aiming to relase rF2 in 2010, and now they are saying that game will be released in 2011. So I won't be surprised if we don't see this game [GSC] by the end of this month.
I've also been watching one of the Brazilian sim racing website's where there was to be a Q&A session, and no one from Reiza Studios has even answered any questions yet.
So, I don't think it will be out in the next few days.
Reiza Studios
"Game Stock Car no longer coming out in April. Some pending details still to be resolved. Good stuff to come as well! We´ll see about reparing something to make up for this short delay..."