Just had an answer from Kunos team : GC has never worked for Kunos... I guess it was only a rumor...so still no clue where he is now, I suppose GC real life does not leave place for simracing anymore ???The last I heard was that he was working for Kunos on Assetto. That's his version of Imola that was originally planned for GTR2. Not sure if he's still there though.
Good luck man.