Are you looking for a set of SE sideskirts? They are three piece bits.
You can also grab some from an S13 and shape them a bit. The S12 door is longer than the S12 but otherwise they fit no worries. Most guys go the S13 for several reasons. They are easier to find, many different styles, they are one-piece, and they are not so hard to find (even though that is the same as the first option
).
I can find you a set of SE sideskirts if you want but I suggest going S13 or any other option the guys offer.