Last night after dinner my middle son (who daily drives the 528, and has communicated interest in buying it but hasn't actually committed to buying it

) mentioned that he heard some strange clunking and grinding going on from the left rear wheel, so I took it for a drive, and confirmed what he described. So I dragged him away from the TV and we jacked up the rear end & pulled the left rear wheel to have a look at things. The problem was pretty easy to spot; one of the bolts holding the brake caliper to the TA was missing, the other was loose, and there was a chunk missing from one of the brake pads. Grand.
He's in an auto shop class at school, and the instructor encourages the students to bring their personal cars in to work on things. The parking brake has been needing adjusting, and I haven't been quick to jump on that project, so a couple of weeks ago he took on the task in class, and was quite proud of getting it done. But apparently he needs to work on his followthrough and make sure that things are buttoned up properly. This is the second time he's worked on the car in class where an issue with loose fasteners has come up later. The first time it was wheel lug bolts; I came home one day to find a lug bolt laying in the driveway, and noticed it came from one of the eta's wheels. Three others were loose enough that I could turn them by hand. He and I had some quality time with a jack and a torque wrench that evening. Then last night... With the chunk missing from the brake pad, I decided a quick brake pad R&R on both wheels was in order. In the dark. In the driveway, In 10° weather. I sure hope that experience will leave a lasting impression on him.
But I'm left wondering whether I should bring this incident up with his shop teacher. I realize the guy can't be looking over the shoulder and checking the work of every kid that brings a car in to work on, but I really don't want the job of double-checking the kid's work after the fact, and I really,
really don't want the job of picking up the pieces after a wreck caused by him failing to put things back together properly. And I would imagine the school would be scared to death of a liability lawsuit resulting from a car that had been worked on in shop class...