Without a sanctioning organization and insurance, I think its going to be tuff to secure a location. I know some auto-x clubs have used the go-kart track inside Lowes Motor Speedway for auto-x events.
Here's a link to a website that can help you find clubs and events near you. I would contact a few of these clubs and they should be able tell you everything you need to know about putting on an auto-x event. You might consider jumping onto an existing event for this year. These clubs don't care...the more, the merrier.
This club ran an auto-x inside the speedway this year...