Both Terminals at Frankfurt Airport have their own car parks - follow the signs from the autobahns or highway. Use the parking garage for the terminal where your airline is located.
Terminal 1 has underground and multi-level parking garages - P1, P2, P3, P4 and P5.
As you approach the airport follow signs for Terminal 1.
For Terminal 2 parking follow the Terminal 2 signs for parking garages P8 and P9.
There is a long term "Holiday Parking" area south of the airport complex on the K823 Airportring road. It is a cheaper option for stays of over three days.
There are reserved bays for users with disabilities at both terminals.