Pics of the 2004 STi hoodscoop on a wagon (mine):
Part numbers needed to install the STi hoodscoop properly for the STi intercooler:
90821FE080NN: Scoop Assy, Hood (hoodscoop, comes unpainted) $149.95 retail
90817FE200: 2004 STi Duct, upper scoop (splitter) $93.12 retail
90817FE210: 2004 STi Duct, lower scoop (rubber shroud) $40.87 retail
90875FE110: Seal, Scoop 2004 STi (thin foam (self sticking) seal that goes between your hood and the hoodscoop. Designed to be taped to the edge of the hoodscoop) $8.18 retail
86636FA120: 2004 STi intercooler spray nozzle. (for waterspray if you go that route) $11.77 retail
90826FA000: Clip $0.84 retail (need 2)*
909130074: Clip, Insulator $0.80 retail (need 2)**
You can obtain the parts cheaper at places like subaruparts.com or other online OEM discounters. Other than one or two aftermarket CF hoodscoops, no one makes a 2004 replica STi hoodscoop, splitter, or other accessories like many do the for the 02/03 models that I know of right now.
Installation is kid simple. Tools needed are a #2 Phillips, 9mm socket, rachet, and pliers. Remove the OEM "splitter" either with a Phillips or the 9mm. You have to get the two screws underneath the hood liner. The hood liner is held in by two clips (** above). Unless you have the special $10,000 tool, you will destroy these clips upon removal. GENTLY pry back the rigid fiberglass liner to remove the screws. If you are very careful with the liner, it should look perfect when all buttoned back up. Sadly, I wasn't gentle.
Once the "splitter is out" you remove the funny 9mm bolts holding the stock hoodscoop.
If your STi hoodscoop has the gasket (mine did), you can now install it. Otherwise, you will have to carefully install the gasket along the edge of the hoodscoop. As the paint guys messed up my gasket, I used the new one for some spot repairs. When bolting it up, press down on the hoodscoop while tightening for the best fit. You may need an assistant or long armed friend for this task.
The STi shroud needs to be attached to the splitter. Carefully remove the plastic rivets from the OEM shroud. Use these for the STi shroud. Sadly, you will be two rivets short. It will still work, but sticklers will want to order two more rivets for perfection. *above listed as "clip" is the plastic rivet. Now the shroud is on the splitter.
Bolt the splitter to the body/hoodscoop. This is also where you would install the new hood liner pins. I didn't have any, so that will have to wait until next friday.
Cost for me: $187.59 for all parts & painting.
I made a few really special deals though, but for the average bear, it should run around $350.
Using the USDM STi components for the JDM STi intercooler still leaves a little room for improvement. The shroud is too small for the bigger JDM intercooler. It is about 1/2" too narrow and about 1" too short. In a perfect world, it should match up perfectly. Since the biggest gap is near the throttle body, where the least amount of cooling occurs, it is fine with me. www.rallispec.com
(and possibly others) sell a Ver 7 splitter for $110. This splitter is specifically designed for this intercooler, but it's price leads me to believe that it does not include the rubber shroud, though I could be wrong. If this was available, it would be the "best" option. Otherwise, discriminating users could modify the STi shroud for better coverage or utilize a custom shroud of their own creation.