If the clubs were to come together, is there land that is available to produce an off road circuit? If so, a government sports grant is an option. Sure, it won't cover the cost of the circuit, but it would be a start. Obviously, the more the circuit is used, the quicker it becomes an asset. Then the options are unlimited to improve & modify the area to make it a high class circuit. This will help it grow into a recognised circuit that others will travel to, and will want to race on.