Now you see, and it has been mentioned on here before, there is a legal right to free access to the footpaths in the area for leisure use, and driving access to them, around the old quarry.
This was specified in the original "planning for leisure"...how the quarry would be put back into public use.
Including, specifically the site of the car park.
Open public access for leisure around the site was a condition in the original planning for the area.
They can not legally charge you for parking, as it is open public access, and that was the designated area for "leisure parking, open and free for all".
This from the wife of one of the locals (Virginia Water) on the original steering committee...the lovely Lizzy of Longridge who I gardened for for a decade.
You only have to say..."I am a walker, let me out for free"...and they have to...allegedly.