Mike, did you actually read the rules or are you listening to someone like Jay ramble? lol 
The show portion of the competition accounts for only 20% of your final score… hell, it’s only there to give the racers a break between events and act as a tie breaker. And since you compete for your class within your team, if your car is ugly as sin it has very little effect on the overall score for the team when compared to the Drag and Auto-X.
The absolute highest score you can get is a 200. (80 points for first in your class for the Auto-X, 80 points for first in your class for the Drag Race and only 40 points for first in your class for the car show.)
So say you were in 10th place in the Auto-X, 19th in the drag race and 30th in the show - your total points will be 141.
Now lets say someone gets first in the Show, but only gets 50th place in the drags and 61st place in the Auto-X - their score will only be 89.
As for just driving the course for fun, that would have to be determined at the event depending on how fast everyone gets through that portion. Any free runs would have to come after people compete.