Hey there, I'm finished with this game but I cant make enough prifit in spectator gambling, if I bet on car 3, i still get to follow car one an cheer and boo him/her out. Why cant i follow an cheer the car i bet on ? Thanks

Well, in the 360 version (what I have), you switch the car by pressing up and down on the control pad, perhaps that's what you do in the PS3 one too.
Also, now you know, perhaps you should try my technique (bet all the money you can on the car with the worst odds, boo/cheer it to victory and claim stupidly large amounts of money)