In reply to Bertbee:
No issues with the barrier last year. We stayed there a few times but the adjacent car park is popular with the local youths in their cars. The Sabot car park can also be busy with locals doing... things... in the car park until late.
If I was going to sleep in a van overnight personally, then I'd do so in the Franchard carpark. If you really wanted to stay local, then the 95.2 car park is quieter. Of course you're not meant to stay in any of them, so I'm sure someone will be on here telling you not to do so shortly...