I think you deserve a medal for getting your camera out at all in those conditions!
I remember a brave, but foolish photographer at a BTCC race at Knockhill (Scotland) having her Nikon DSLR die due to rain getting in - even the 'weather sealed' pro models have their limits - I've seen various plastic cape contraptions used to try and keep things dry - or even a shammy leather draped over the camera and lens...
Were you able to get close to the action, or have you cropped the final images to get the frame filling comps?
BTW - love some of the pit-lane shots, and also this strong comp as well - great idea!