I would normally set the player's gani and just send parameters to the gani to control the angle of the car (using a gani script). This effectively hides the players and makes sure that all other players can see the rotation of the car.
From my initial inspection, the only thing I can see that would be causing a movement issue is that you should do:
PHP Code:
player.x -= cos(this.ang) * 1;
When I have more time, I'll take a further look at it. But, play around with it more and let us know if you have any success
.