I checked it the other day and it showed up but said availability date unknown.
I am too am torn, because he raced against and even on the same team as Senna I feel like Prost does not always get his due. Then again it was an amazing era in Formula one with Senna, Prost, Piquet, Mansell and at the tail end Schumacher.
A while back I read Senna versus Prost by Malcom Folley and its a good read especially if you are a fan of Prost as he did some extensive interviews with him.