I put my Hayden under the battery box. Mirror to the space the air silencer sits in on the passenger side.
Reason one: The cooler is protected from stones and other objects coming through the air dam/grille of the car.
Reason two: Short runs for cooler hoses. I had more that enough hose from what bulkpart.com had sent.
If you know what you are doing, (I didn't and needed help) you won't need extra fittings or the install kit Bulkpart sells.
The Parts Bin Special is DEAD! It is being parted out.