If you fancy car-sharing to the Festival, try GoCarShare, which helps you find a car share using your Facebook account. You can also try BlaBlaCar or Liftshare, which can help you get in touch with others either offering a ride or needing one.
When car-sharing, make sure you know the identity of the person or persons you are sharing with. Take a note of their home telephone number and leave details of the lift-share, the driver and passenger's number(s) and home address if possible with friends and/or family. Take your mobile phone with you. If you are at all uncomfortable with any arrangements, or the condition of the vehicle being used, then make other plans. If a vehicle is not taxed it is possible the driver has no driving license, no insurance and no MOT.
All arrangements which you make are private arrangements between you and other sharers. The Festival does not arrange lift-sharing or have any liability to or for lift sharers.