I can't speak for other dealerships but I do it every day, and I'm pretty damn thorough. I drive every car and then check it out, documenting everything wrong with it (aside from minor cosmetic damage), make my recommendations, and correct the issues when the work gets approved.

Every car we sell must pass a basic safety inspection. This mostly consists of making sure the brakes and tires are at least 50%, lights work, the suspension and steering components are still properly attached to the vehicle with no play or busted boots, and nothing is pouring fluid on the ground. Certified pre-owned cars and also ones that carry our however-many-day warranty have more strict qualifications.

Now, there are a couple issues that come up.

1) they don't always follow my recommendations aside from basic safety on non-certified cars. On minor issues sometimes it's just "fuck it", on bigger issues they try to sell the car "as is" until the customer complains and then they realize they should have just sent it to auction.

2) sometimes they sell the car before I've even inspected it, and sometimes this has them feeling stupid when they see the bill (which doesn't stop them from doing it again).

3) the salesperson you're talking to may or may not have actually read my inspection sheet in the first place (but the manager has because he has to approve or deny any work over $1000)