If you intend to go, learn the circuit on 'Grand Prix Legands' game. You don't get the changes in altitude, but at least you know which way the next bend goes!
It is really hard to learn, I been several times and have done many laps in various toys (not a Golf yet), but still don't instictively know it all, yet.
Clarkson was very lucky not to stack the Jag - there really is NO margin for error. Two of my pals have stacked their Porkers at the 'ring (no pun intended).
To view a fast lap, driven by my mate Barrie, go to
www.trackfun.co.uk, go to 'multimedia' and 'click the link' for a fab lap around the 'ring with Baz chasing the M5 Ring taxi!
Enjoy.