Jumping right in with your cylinders in boxes and form intersections, you're demonstrating a clear and well developing understanding of most of the spatial relationships here - the box-cylinder-sphere on the upper right corner is an especially nice touch. I did catch a little bit of an issue with this cone/box intersection, primarily with that vertical line cutting straight down the side of the box. The rest look solid, though.

Continuing onto your form intersection vehicle constructions, you may be concerned that you didn't do enough on these, but I assure you, this is what I asked for. A lot of students overthink it and go way further, but all I really want here are primitives arranged in the general plan of vehicles, and that's precisely what you gave me.

Moving onto the meat of this lesson - the actual detailed vehicle constructions - I'm left feeling a little uncertain. It's very clear that you've knocked this out of the park, and that you are without question demonstrating all of the skills and understanding I want to see from this lesson. The issue is really just one of approach.

It's not that uncommon for students to get so excited to be at the end that they skip steps, draw more from observation, or in other general ways throw the techniques shown in the lesson out the window. You've done that too, albeit really only in this drawing which by no means fits what the lesson assigned. That is, the lesson, like all lessons before it, asked for constructional drawing exercises. It's not an opportunity to show off what you've learned, but rather a last chance to ensure that students understand how to continue developing those spatial reasoning skills as effectively as possible as they go forwards.

So, the motorcycle does not fit that at all, given that you're not drawing through your forms, you're focusing only on keeping things clean, and so on. The others however, while they do employ a variety of approaches, some of which break away from the bounding-box-with-subdivision approach (like this really cool airplane), they do still demonstrate a clear focus on understanding how your lines converge towards consistent vanishing points, and generally maintaining consistent spatial relationships. If anything, it's more that you dismantled the concept of the bounding box, and kept only the pieces that were relevant to the problem you were solving. We see something similar with this car.

I am admittedly pleased to see that you did still employ the more formal bounding-box approach in constructions like your train and your quad bike. The only other one I do want to call out is this truck - with your lines going back to plotted vanishing points, it really becomes more of a technical perspective exercise, rather than the kind of organic construction we're looking to do here. But in the grand scheme of things, with so many other successful constructions, it's not really a big deal.

The last, and perhaps only real piece of criticism I want to offer is really more of a stylistic one. In drawing this tank, you ended up going for a lot of heavy hatching. I've found that with fineliners, or anything that creates really bold, dark strokes with no real midtones (like what graphite or even ballpoint would give you), hatching tends to just become almost painfully noisy, and makes it very difficult to establish strong focal points. Instead, I would definitely focus on creating specific, designed, intentional cast shadow shapes, allowing them to be filled in solidly to help keep that overall contrast down. Some students try to mix this with hatching, but it really just makes it a muddy mess. Of course, working with such strong shadow shapes can be very daunting, but once you start, you'll be amazed at how freeing it is.

So, with that, congratulations! I'll go ahead and mark this lesson, and with it the entire course, as complete.

Edit: Oh! I forgot to say - thank you for the kind words! It is my honour to help students establish a strong foundation, and I'm always excited to see where my completionists go next.