Montpellier Airport Car Park
There are four public car parks at the Montpellier Airport, P2, P3, P4 and P6. You can park in any one you like, but in general P2 is for short term parking and P4 is for long term, see tariffs. For anyone parking for more than seven days it's possible to pay a flat 18€ - Car Park Pass for 18 euros. I suggest you ask at the car park office on the ground floor of car park P2.
When you enter any car park you take a ticket. Save it as you will need it when you leave. You can pay at any of the payment machines at the airport. You input your ticket and then pay. Payment can be made with a credit card or cash. I believe that only cards with a chip, i.e. code will work on all machines. Once payment is made you have 15 minutes to exit.
There are two payment machines in car park P2 and one at each end of the airport terminal.
There is also a P0 car park with 180 spaces, which has a fence and camera surveillance 24/7. It is run by CAR HOTEL (web site in French). It can be a bit pricey, starts at 17€ per day but it's possible to wash your car or even to get refueled.
If you have luggage there are baggage trolleys in each car park.
Car park P1 is for car hire.