As a whole, I am quite pleased with your results, and assuming that your imgur gallery was uploaded in reverse chronological order (which makes sense, since the cylinders and form intersections are at the end), you've definitely shown considerable improvement and growth over the set and should be very proud of what you've achieved.

Starting with your form intersections, the main issue I noticed here was that some of the basic form constructions here were admittedly kind of clumsy. You shouldn't be overshooting your lines so much - that is a great way to analyze your results afterwards, but when doing the exercise itself, you should be only drawing the lines as long as they need to be to define the forms themselves.

Additionally, the pyramid on the far right has a critical issue: you've got the height of the pyramid mostly visible in a way that suggests that it's moving across the viewer's field of view, rather than moving primarily through the depth of the scene - but the square base of the pyramid is wide enough that it suggests it's looking at the viewer head-on, which only occurs when the height of the pyramid is primarily moving through the depth of the scene. It's important to keep in mind how the form itself is oriented, and how the different dimensions of the form need to be depicted to maintain that in a consistent manner.

Continuing onto your cylinders in boxes, these are fine (although just 2 to a page is a bit low). Just take more care to execute your ellipses more confidently, using the ghosting method to keep those ellipses smooth and evenly shaped. You appear to have hesitated quite a bit when drawing them, more concerned with getting them to fit snugly within the planes. Remember that as discussed way back in lesson 1, the confidence of the execution is first and foremost. Accuracy only comes afterwards.

So by the end of your vehicle constructions, you're doing great, but your first few drawings suffer from a few key issues. They're actually not that bad either - you're going through a lot of the right steps, and you're showing a fair bit of care and patience to pin down a lot of the necessary subdivisions and thinking about how your lines all converge consistently. The key issue is actually just that you're biting off way too much - you've decided here to draw the earlier vehicles freehand (at least for the vehicle itself - not sure if you were freehanding the underlying bounding box and subdivisions).

The reason I give students permission to use ballpoint pens, rulers, ellipse guides, etc. in this lesson and in lesson 6 is not to be nice. It's easy to come to that misconception, and to end up feeling the need to freehand them anyway, but to do so would be a mistake. The subject matter we explore in this lesson is a lot. It's complicated, and requires you to put all your brain power towards figuring out how much you need to subdivide things, to observe your references carefully, and to really drill down through a lot of complexity. Freehanding your linework while trying to sort through this mental maze is just way too much to reasonably ask from a student who's doing this for the first time. It's not that you won't be able to do it freehand - just that our focus here is on learning a specific lesson, and we've gotten to a point where having students worry about freehanding their lines diminishes our pursuit of that goal. Some students will see this as a loss of opportunity to improve your freehanding - but we have loads of exercises that specifically focus on that earlier in the course.

Anyway! That's all neither here nor there - because after the first four drawings, you very clearly started making much better use of tools to help you focus on the specific challenges and exercises laid before you, and as a result you did a great job. You nail the core structures of your constructions, and also pin down a great deal of complex, nuanced detail without breaking away from the principles of construction. As a result, your constructions feel solid and three dimensional. Your cars towards the end are especially well done.

In the cars, I can see areas where you find that your drawing diverges from your reference. This is a natural thing that happens when dealing with such a complex subject matter, and of course as one practices (and as one specifically studies a particular model of car) your drawings will get more accurate. What's more important to me, however, is the fact that you're rolling with those punches. You make adjustments where you know it won't undermine the solidity of your structure, and leaving things alone where you've gone too far down a particular road. The result remains solid, which is always our main priority.

Stepping back a little, there is one minor piece of criticism I do want to offer, which relates particularly to the use of line weight. Especially in your earlier drawings (the ones that relied on more freehanding), you seemed to have a pretty inconsistent use of line weight, so I feel it may be worth reiterating what this tool is for, and how it should be used.

Line weight serves a very specific purpose - to clarify how particular forms overlap in specific localized areas. Rather than trying to reinforce the entirety of a form's silhouette (which you often ended up doing here, especially in drawings like this one, the key is to use line weight in little places. We want to avoid tracing back over existing linework because it's going to come out hesitant and will focus too much on how the lines themselves sit on the flat page, rather than how they represent edges in 3D space. Instead, using the ghosting method as we would for any mark we'd draw is far more effective - it yields more confident, smoother strokes which end up tapering towards the ends to more smoothly blend back into the existing line you're reinforcing.

This, along with focusing that line weight in localized areas, to clarify specific overlaps, will help give your drawings a greater overall sense of depth and dimension, without feeling clumsy or flattening out. For the most part you did a better job of it throughout your later drawings, but in cases like this tank the choice of reinforcing the silhouette of the tank with more line weight did end up somewhat flattening it out into more of a graphic shape. So, just be sure to continue to keep that in mind.

Aside from that, you're doing quite well. With more practice you will undoubtedly continue to improve how accurately you're able to capture specific details, and the tendency to elongate your cars should diminish as well. What's important is that you're headed very much in the right direction - and as with all things in this course, the goal is to have you walking down the right path, and to leave you to continue marching down it confidently.

So! I'll go ahead and mark this lesson as complete - and with it, the entire course. Congratulations on your achievement!