On the latest info about Hullavington, the email say you can hire their Elise for 10 mins..
Lotus Elise Hire at this event
This is your chance to drive this fantastic sports cars. For just £30 you can drive one of our Lotus Elise sports cars with an instructor in the passenger seat coaching you for a 10 minute session. We are also offering high speed passenger rides in this car at £20 for three laps. These sessions can be booked in advance by calling us or on the day if space is available.
Cheap, short time but will give intro to how safe it can be.
But if you want a full day there is plenty that do Caterham/Elise for hire but they normally cost 3-400 a day.
Steve