There is concern about using vehicles "laden", untaxed, etc at shows because as the law stands road regulations apply in these areas as they are accessible to the public. You can see the reasoning, safety, insurance etc.
If these were segregated areas, ie all arenas and "pit" areas in effect fenced off, so as not to be accessible to the public, could this be a way around the problem. I know we want the public to be able to see the vehicles up close, this would not effect this if vehicles were in the "pit" and arenas only when neccesary and returned to the public area after their turn. Moving in and out would be the only time of risk but under marshal control this could be done safely, possibly even legaly. The area under temp. marshal control in effect not accessible to the public!
Just a thought.