Yes, on the ACC, makes sense, but I know I've seen YT vids with it working. But I will check with it with "radio" as SRC. If not, I'll just hook it up straight to fuse like seen from Johnny Tsunami.what are you using to power the camera? If its the blue ANT wire, it might not be powered unless the source is set to radio. So set the head unit to radio and see if the camera works. If it does, then you need to run a switched 12v acc wire to the camera off the fuse box, or use a wire tester and pull it off the AUCar harness. It's a weird setup though, Maserati uses CANBUS for on/off signal, so there might not be a ACC lead in the harness. It might be the red wire on the harness of the AUCar, or you can pull it off the ACC fuse on drivers side fuse box under your knee area.
I did order another camera, so I will try that as well.