Your car is 5 years newer than mine, but I will make a guess....
Open your cars hood, and go to the passenger side and look at the Cowl Vent screen. If you have these little pin looking things that have a head that looks like a flat headed screw driver, chances are your is under that cowl screen.
In my 97 is shows where and how to change it in my owners manual, take a look and see if its in yours....
Hi I know you are frustated, but once I tell you how to do it, you will find it real easy. I assume you bought the replacement filter: "Passenger Compartment Pollen Filter", FP-54 (4F1Z-19N619-AA). If you buy it from Ford you will pay alot. I saw it on Ebay for $10:
1. The filter is underneath the windshield and windshield wipers. Under the black airscoop.
2. Leave the hood shut, take a thin blade and pry back the plastic air scoop and the retainers will pup-up. You only have to do this for the half side of the passenger window. Do not go past the center mark towards the driver's side.
3. Open the car hood and you will find three clips holding the upper half and the lower half together. Be careful to hang on to them. You will need them to put them back.
4. There is one(1) screw you will have to remove and again hang on to it.
the screw is at the end of the black platic air scoop behind the McPherson Strut.
5. Lift the two halves of the black airscoop apart and you will the pollen filter staring you in the face. Mine was full of leaves and totally black. It only had 39,000 miles on it. Definitely have it replaced per the recommended interval. Mine was just about totally blocked. I have the 2002 Taurus SW.
1. Open the hood.
2. Remove the 3 clips on the forward edge of the R. screen. They hold the washer and vaccum lines too.
3. Pull up on the back edge of the R. screen to disengage the retaining clips that hold the R. screen to the windshield frame and remove the screen.
4. There is a plastic drain deflector directly over the filter. Remove the two 5.5 mm bolts and slide the deflector to the L. until the mounting bosses on the deflector clear the windshield frame. Then just slide it forward to remove.
5. Pull up on the filter to remove.
6. Take your new filter and insert and push down the R. rear corner first. Then push down on the rest of it until it is evenly down all the way around.
7. Reinstall the deflector by sliding it in so the mounting bosses clear the winshield frame then slide it to the r. until the bolt holes in the mounting bosses line up with the windshield frame holes. Now reinstall the 5.5 mm bolts. The flap on the R. side of the deflector is flexable to make removal and installation easier.
8. Reinstall the R. cowl screen by lining up the retaining clips on the back of the screen with the slots on the windshield frame. Now just push down on the screen until the clips click.
9. Reinstall the clips on the forward edge of the screen and you are done!!!
The filter is available from WIX Filters for about $18. Good Luck.