Safe open space in or around London???

[jdharris]

This may be a strange request (and a long shot) but does anyone know of an open space in or around London where I can take my girlfriend to let her find out what the loud pedal on my TVR does without fear of her putting it into a hedge? Something like an old airfield or carpark would be ideal as long as I wouldn't be upsetting anyone. I don't certainly want any trouble so please don't suggest anything that would interest Plod or upset the neighbours...

Is there anything that fits the bill around SW london or am I going to have to pay for some track time?

Thanks in advance.

[noumenon]

www.carlimits.com - activity day is an option. Should be £20-40 to have a lot of fun. Plus some great instruction too. It's M25/Essex, but well worth the trip.