How many times are you actually stopped by LE? Don't you think that once you've killed a time or two, maybe sweated bullets the first several times you've transported a victim, you become as comfortable with it as driving to the local store?
The few times I've been stopped: Driver's License checkpoint, speeding, temporary tag, LE has never had me pop the trunk. Once in the dark, they had a flashlight and saw my two dogs in the back. He could not see the temporary tag in the back window, then apologized for stopping me. Another, we had a packed station wagon returning from vacation and were stopped in the mountains because of an intense manhunt.
The percentage of trips in which I even came under any scrutiny is so miniscule that someone like RH seeming like a good citizen with his story ready and a locked cover on his truck was safe. From reports, people with tail lights out or some other preventable cause for stop should not be carrying drugs or running stop signs or giving anyone cause to stop and search. But the ordinary citizen? The odds of ever being stopped are almost non-existent.
I think the first few times would be nerve-racking, but after that? No, perhaps just part of the game.