Many people in their sporty weekend driver, or ever their daily driver sometimes might want to know their intake temperature at the air filter. This can be useful knowledge for many things such as, performance, gas mileage, and air/fuel tuning.
This is what I am going to call a free modification, it will cost you approxmently $1 at your local hardware store.
NOTE: In order to complete this modification you must have the in-dash outside temperature display in your gauge counsel.
On the front of the car on the driver side edge of the radiator locate your external outside temperature sensor (this will look like a 1 inch black probe towards the bottom of the radiator).
Either measure the diameter of the black probe with a caliper, or remove the black probe from the wire harness.
Take the measurement or the probe itself to your local hardware store and buy a rubber grommet that fits snuggly around the black probe (use some force to make sure it is a nice tight seal).
Find a drill bit slightly smaller than the outside diameter of the rubber grommet. I prefer a step bit so I can test fit it to the perfect size needed to make an air tight fit.
Remove any extra clips, tape, and housing that is retaining the sensor wire so that you can position the sensor wire at the side of the air.
Insert the grommet into the airbox that you have drilled. then snugly insert the temperature probe and connect wire harness.
Take the car for a drive to check that the setup is working. you should see change in the temperature under different driving conditions.