mine came with directions. I would keep it under the dash. you just have to wire through the vacuum line or use the boost gauge line to tape off of. mine is under the hood since the maf wire (middle one) was easy to get to, i had a good ground, and i could T off a vacuum source. i'm moving it this weekend.
the fcd is so BALLER, i can acutally floor it @ night and it pulls like a mother. it was rough and sluggish but everything is smooth. right now for me 2nd gear is basically useless with brand new es100's i just got. not that loosing traction is a good thing, you are actually slower but shows my hp increase and delivery. later.