In US, as far as I know. You are not do anything illegal. Because you are not on the public roads or streets, you are on a private property. US are sue happy so they protect as much as they can. Driver have to obey by rules and regulations. The car have to go thru intensive tech & inspections. Some time people still be able to sue somebody if they can proof that somebody are not do what they suppose to do. For example: driver drive a car that have a bald tire and the tire blow up cause someone injury. He or she can sue the driver, mechanic and team for negligent to use a save race able tire.