Forgot to mention:
I've competed at the "MotorSport at the Palace" event, organised by the Sevenoaks MC at Crystal Palace. It's a sprint as the old course alonside the National Sports Centre now is commandeered for car parking (!). It starts on the pathway past the Concert Platform (Square to the left of The Glade corner, on the map on page 1), goes north and turns sharp left, then sharp right and again onto the end of the old Terrace Straight, around a chicane where the start path joins the Straight and on around North Tower and the Glade, to finish just before Park Curve. Around the Curve, sharp right again and back to the lovely wooded area next to the star which was used as the Sprint Paddock. The old Paddock was classic clubs' displays and parking.
It's a worthwhile event! This year's has gone by, but look out for 2014! See:
http://www.motorsportatthepalace.co.uk/
And see:
http://www.solitude-revival.org/
for Solitude (in German)
John