So I finally got all my parts (Nismo cai, HotShot header, & Nismo cat-back) and I got the pleasure of installing it all today with a mechanic friend of mine. It took us the whole day (7 hours) to install everything correctly including the O2 sensor relocation. I'm very happy with the way the car feels and sounds. The header was the most PITA overall. Even after reading different accounts of installing it as well as all the write-ups, I was still a little surprised at the ***-pain level. Oh well. It's all done now. I think the next thing I do before suspension is probably order some front MMI from ES. What is everyone's take on those? If I just do the front I'm thinking the vibrations won't be too bad.