Lampshaded in the Season 5 pilot, where Andrew Younghusband says "Welcome to the country's most disturbing car show". What better page quote could we ask for?
This show only accepts legally valid drivers. In other words, all contestants have valid driving licenses and are insured. This doesn't include drivers who've had their licenses revoked, or who're too incompetent to pass in the first place, or ones who don't have insurance because it's too expensive for bad drivers to be insured (though some can get by on other people's insurance)...
The "insured" part became important during season 6 - Scott's unwillingness to learn caused his roommate and nominator Danny (who paid for Scott's insurance) to become fed up, verbally rip Scott a new one, and cancel the policy. As a result, Scott got booted off the show.
Another said she flirted with the driving instructor, with success.
Henrietta in season 2 becoming completely unresponsive during the final road test.
Jason Zhang in season 3, stopping in a merge lane in Highway 400.
Season 6, Dale chasing Andrew with the car. She joked that she was toying with him.
In the third episode of Season 7, it was pointed out that all of the contestants had confessed to having driven distracted. So, they set up their "easiest" course ever ... made harder by intentionally making the contestants drive while subjecting themselves to distractions (such as food, and the classic "texting while driving"). The results were predictable, but got downright scary when Tab almost made the old 1950's car roll over on Styrofoam.
This doubles as a Tear Jerker because when they finished they had to have a conversation with Aaron (who, six years prior, was nearly killed by a distracted driver) - in said conversation they had to look Aaron in the eye and promise to never drive distracted again. Everybody cried.
Sadly, CWD Ever proved that Sly, one of the Season 7 contestants broke this promise, despite seeing how it affected Aaron. (Although Sly's case may be partially justified as he has a learning disability)
In season 8, during the Eye of the Needle challenge, Flora lost control of the Mustang, going off the road at around 140 kilometers per hour (around 85 miles per hour). As a result, the car went into a sideways skid, going for at least 25 feet. If she had hit an uneven patch of ground, she could have easily flipped her car. She also knocked a bumper off it.
Kevin's final road test in the Ever finale. It was becoming so dangerous that after Kevin drove into oncoming traffic (again) and nearly collided, Andrew had to stop the road test for fear of their own safety.
The distracted driving challenge in Season 10 is bad enough, but Chanie takes it one step further by nearly flipping the car while trying to take a selfie, running over a block of Styrofoam. Even the panel were shocked and the crew actually had not anticipated this sort of thing could happen at all. Realizing how close she came to being injured alongside with her boyfriend (who had nominated her), and how easily it could happen if she did the same thing with her son also in the car, Chanie broke down in tears.