Note: This is an addendum to Eli's $9 CAI .
Please look over those first as the instructions are much better.
This is really just a description of the pictures I took while building mine.

Parts:

• (1) 9"x9" Catch Basin $10.00
• (1) 10"x8" plexiglass $2.00
• (3) 3/4" bolts + nuts $1.00
• (5ft) 16" width Reflectix Material $5.00 ($1.00/ft)
• (1) Roll of Reflectix Tape (or Tin Duct Tape) $3.00

Tools:

• Jig Saw
• Utility Knife
• Drill
• Sanding Bit

Procedure:
1. Draw a 4" hole that the K&N cone will go through the back.
   You want to make the hole towards the top of the box.

2. Cut out the 4" hole.

3. Cut out the side that goes to the Fenderwell.

4. You have to cut the plexiglass to make the side that is flush with the fenderwell.

5. You have to cut off the little supports on the top of the box to fit the plexiglass there.

6. Put the Plexiglass on the top.

7. Drill 3 holes and bolt the plexiglass onto the top.

8. Cover the side with Reflectix.

9. Cover the rest of the box with Reflectix.

10. Install the box in the car.