I got some factory drilled, slotted rotors (basically for looks) I looked online and it seems they are setup both ways. looking from the Left side of the car (towards the car) the top half of the rotors, I have seen the slots go both ways. which way should it be? I thought it would be where the slot started closer to the center of the rotor and pushed outwards as the rotor turns, correct? does it even matter?

 

It depends. The internal vane is what determines the direction. If the vanes are curved, then they are directional and should only be installed one direction for proper cooling. If the internal vanes are straight, then they are non-directional and can be used on either side.