The installation pics at the beginning of this thread (WilliamK10's pics and descriptions) are really excellent and got me thru my install. the ONLY thing about them is the pic of where to fish the wire out thru the firewall, his pics he has an aftermarket intake.
My car is stock, so I had to remove the battery and air box to get at the plastic/rubber grommet thingy you pass the wires thru.
THe hardest part of the procedure was getting the battery back IN because the mat/tray thing didn't want to lay flat (there's little tabs that go into holes on the top of the transmission or whatever it is sitting on) and the hold-down bracket was a HUGE PITA to get back onto the edge of the battery. At least while I was in there I could clean up the suprising amount of battery corrosion and bugs that built up on there.
Well, the other hard part was trying to find something to ground the wiring to. THis is my first new car (at age 40) all the other cars I've had had been 10-20 years old and had way more metal than plastic around to tie into.