Everybody's responsibility? To check every vehicle at a rally is taxed and insured?! My responsibility ends at paying over inflated premiums due to the none insured morons....And also paying my council tax to pay for the Police who seem to be taking uninsured vehicles off the road.
Most of the rallies I book into request insurance details if the vehicle isn't just a static display, which is great, I wouldn't however want to show my cover note to some mithering idiot at a rally field.
If you use an uninsured vehicle on public roads, you deserve everything that you have coming.