There is not one on the 500
Try this link for a Cabin Air Filter mod for Ford Freestyle or 500. http://www.myfordfreestyle.com/forums/viewtopic.php?f=2&t=1288
I have a 2003 ML 500, and have changed the cabin filter twice. Mine is located on the underside of the dash panel on the passenger side. There are a couple of screws that must be removed to access the cabin filter. It's a body bender job, but only takes about 15 minutes.
According to the 2006 Ford 500 Owner Guide : ( Motorcraft FL-820-S )
I believe it is to the left of the air filter ( looking from the front of the vehicle )
Right on top after the air filter. It is expensive but a very easy switch out
( 6 quarts ) with engine oil filter change , according to the 2006 Ford Five Hundred Owner Guide
( 6 quarts ) with engine oil filter change , according to the Owner Guide
According to the 2011 Ford Escape Owner Guide : For the 3.0 liter V6 engine ( Motorcraft FL-500-S engine oil filter ) For the 2.5 liter four cylinder engine (Motorcraft FL-910 engine oil filter * ) ( * I was looking at www.fordparts.com and it shows part # FL-910 as being a spin on type of oil filter , apparently there is also a cartridge type oil filter , but Ford doesn't show the part # for that )
Only Ford wold know for sure but the name 500 was used by Ford in the 50s & 60s on the Fairlane 500 and Galaxy 500. I guess Ford just decided to use it on the car that replaced the Taurus.
For the ( 6 ) speed automatic transmission it is by the engine air filter housing according to the picture in the Owner Guide
Cabin rental rates can vary depending on location, size, and amenities. For example, Gatlinburg, Tennessee has cabins for as little as $99/night and cabins that are $500+/night. Prices depend on the number of bedrooms and bathrooms as well as amenities like a pool or deck.
The combined MAF/IAT sensor (6 wire plug) is on the air intake duct just above the air filter.