There is also a small exit if you are parked at the far end from the entrance. as you drive into RPR over the bridge ,there is a small pedestrian crossing just when you turn right to drop off at the door of RPR, if you look to the left at it you will see the exit, saves walking right round if you are parked at that end.
You used to get free parking if you had disabled Placard, but this changed a few years ago and everyone pays now, although would do no harm in asking when you checkin, as like mac said, some people have got it while others have not.