The big event this weekend is the Hutton Kitchens Brands Hatch Summer Stages on Monday:
http://brandshatchstages.co.uk
http://www.mcsrallyresults.co.uk/2012%20HKBHSS.html
There is also a round of the the Jam Jar Autotest series on Sunday:
http://www.wickfordautoclub.co.uk