Yes, it is identical.
I believe the "Related Question" below specifically addresses replacing the door glass on a Taurus / Sable.
No. 2000 Taurus and Sable are the only interchange.
If it's like my 1999 taurus, it is located on the underside of the rear dash inside the trunk.
In a 1998 Mercury Sable : The transaxle is the transmission on your front wheel drive Mercury Sable it is located in the engine compartment , on the drivers side , bolted to the engine
According to the 1998 Mercury Sable Owner Guide : ( 16.0 U.S. gallons )
1999 mercury sable horn replacement
Yes - the filter is outside the tank, which is where the fuel pump is mounted. See "Related Questions" below - The Taurus information applies equally to the Sable.
front of the motor
Replace it with new tubing.
You have to learn all the new controls(??)Seriously though - See "Related Questions" below for more information about dash converter kits for this generation of Taurus / Sable and how to install an after-market unit.
The transmission ( or in the case of your front wheel drive 1998 Mercury Sable , the " transaxle " ) is located in the engine compartment , on the drivers side , bolted to the engine
R134a