I know its not a Subaru but hopefully you can help.

Just swapped the discs and pads on my Octavia to Group N slotted and drilled with Greenstuff for the road and red stuff for the track. Kept the original size (312x25) but when fitting I suddenly thought, which side is which or doesn't it matter? I assumed it did and made a best guess. Then I saw the picture on here of the before and after AP upgrade, mine are on with the grooves as in the before picture should they be on as in the after picture?

Thanks.