Sorry to sound like a damp squid, but I went last year. The main reason was to see the launch of the "new" MG car range as well as see the motor racing machines for the Le Mans, BTCC and rally programmes.
I personally thought it was full of MGB fans, midgets and beardo's.
No, I'm not joining Nat. I admit there maybe loads of benefits - I believe the Silverstone Meet for example allows only members to join the parade. Although as mentioned I am open to persaussion. If we go Sunday - this may swing it.