I went through this law in a discussion on another list several months ago. I read and re-read that passage (and another accompanying passage) several times and had to sit down and break it down in to little bits to understand it.
Basically, we (friend attending law school and I) think it was for the days of the "good 'ole boys" in Charlotte and their NASCAR vehicles being driven on the street. They would say that they weren't driving x car because it had a different engine in it or an engine from another car - this law countered their loophole defense so they could be nicked for speeding. There is another section that might not have been quoted earlier which would make my explanation clearer...I'd have to do serious digging to find it, though...
It's one of those old blue-laws that they will use to get you...given that someone would be operating THAT (looking at picture) on the street, I think they needed to be nicked based on that law. I'm sure they read them the riot act and have piled up other charges.
The funny thing is the officer's statement about people lined up beside the road. Uhm...officer friendly obvious has NOT seen some of rally videos I've seen.
Then again, I often wonder why people would get that close to a speeding car without safety barriers and even then, they aren't a safety guarantee for a bystander who is actually alert and aware of the possibility of a hazard (I'm thinking flagger at a track), let alone a bunch of joe-blows just standing 'round watching a race....
--Ashraf