Just to report back... I uninstalled and reinstalled the game (first making sure I was linked to both Google Play and Fb) and the prize money now makes it into my account! :) Weird bug. Still means I'm probably $100k down from no prize money for Classes D through A wins :(
Just did the same thing to me in another class. I selected the McLaren...then it "needed a restart" and now its switched to a Dodge. I have to say that I like the game, but I've now spent about $30 on credits and this game is nowhere near the quality required for a paid app. I am missing credit from winning races…
I'm in the same boat...having to "buy" cash for this game because I'm not accumulating the money I win seems pretty unscrupulous. I'm up to about the same stage as you and so I'm so also a lot out of pocket!! Galaxy Note 3 here running 4.4.2