The UK season is coming to a close, the outdoor national and Regional series that is. Many clubs hold a winter series starting in oct or nov. There is also plenty of indoor racing throughout the winter, 2 big meetings will be the Petit race and the Players race. The two closest clubs to London airports are Eden Park,
http://www.edenparkraceway.com/ and Stotfold,
http://www.stotfoldmcc.co.uk/ .