I found a really good shop to install my system. Caton Radio on Route 40 in Catonsville, MD. The manager of the place, Hossein, and almost all the installers, own 350Z's, so they know the car REALLY well.
I would highly recommend them. Since I was bringing in a Z, they gave me a great deal, and their install was so clean, you probably would think it was a custom job.
Ask for Hossein (SeinZ, on "the other forum") Can't recommend these guys enough!