I'm with rspears on this one... just lay it out for the agent and maybe you'll get lucky. There is race car insurance available but I don't know that any will cover incidents occurring on the track... there may be some listings in National Dragster. We have a local insurance company as a minor sponsor at our track that covers race cars.... your incident here has me thinking I should upgrade from good ol' State Farm.

Good luck getting sorted out...

-Chris