1. it should be targetAngle = angle(car.x, car.y, target.x, target.y)
2. you should compare that angle to the angle of car, so if targetAngle < car.angle it turned right, else it turned left.
But also there is problem with angle 0 where 0 becomes 360, so it should be:
if targetAngle < car.angle = right
if targetAngle > car.angle + 180 = right
else = left
Hope it helps, if you give capx maybe I could help more.