http://www.modelaircraft.org/members.../overview.aspx
Services:
Liability Coverage for the Operation of Model Aircraft, Boats, Cars, and Rockets

Now a consideration: About 8 years ago, a group came to my main club and wished to build a dirt car track. After due consideration, the club agreed to furnish the area. We extended water and electrics to the area. The understanding was:
1.) Car members would take care of their yard-work themselves. After all the club owned the land, paid the real estate taxes, the electric bill and owned the well that furnished water, along with the indoor rest facilities.
2.) Car Club members would pay an annual membership fee equal to 30% of flying member dues. AMA membership was NOT required. Car members could not fly except for whatever might be available through the AMA Introductory Pilot program, or by joining the main Club as AMA members.
3.) They did build a nice track, however in a short time they wanted the regular club's mowing and work crews to also take care of their car site. When that did not happen, they were gone within several months and the place was a mess. After a year or so the RC Club had to dismantle the track, clean up all the pipes and metal fences, etc., and rebuild the aera which returned to the acrage available to the Hay Farmer that leases from the Club.

That is my story, you can decide your case for yourself. [:-]