Starting with your form intersections, for the most part you're doing pretty well, but I did catch a couple of cases where you had some trouble with intersections between curving surfaces. Here the issue was more that in your uncertainty, you ended up drawing some rather unconfident marks, which I've corrected here. While it's natural for our uncertainty to show in our markmaking, there's no actual benefit from it. Instead, it's best to make a conscious choice in how an intersection should be defined, and then committing to that choice with confidence, even if it's wrong. This will give us a better chance of capturing specific curvatures.

In turn, you'll also notice that I drew some little arrows on the page defining the curvature of different forms' surfaces. Doing so (I'd usually do this in my head, mind you) helps me think about the nature of the intersection I'm dealing with. If I look at each form's curvature independently, it helps me make a more conscious, structure choice about how those curves come together to produce a single intersection line, since the intersection will inevitably transition from following one of these surfaces more directly, to following the other.

Now it's worth mentioning that for the most part you have still done well - you've got some really nice intersections between spheres and boxes, and even a tricky cylinder/cone which was solved correctly. So as a whole, you're definitely progressing well here, there's simply still room for growth, as there always is.

Continuing onto your cylinders in boxes, these are similarly coming along nicely. I can see that some of your contact points are a little off at times, but that really is totally normal. This kind of exercise is very challenging, and will show progress more gradually than some of the others we've tackled, simply because of the hard-to-predict nature of ellipses. What's important is that you're on the right track here, and that you're analyzing your work after the fact to continue improving your instincts.

Finally, onto the meat of this lesson - your vehicle constructions. For the simpler ones - like this race car, you honestly did go well beyond what was asked for here. It's nothing bad of course, but it probably could have been a bit easier on you. In this one there's no need to worry too much about strict proportions and subdivisions - the focus is really on laying down primitive forms and combining them, just as one would in the form intersections exercise, but following a specific likeness as your end goal. Think of it like playing with legos.

Of course, the patience and care with which you've tackled these really does serve as a preview for how you approach things when you really go all out. Your later, more developed and detailed vehicle constructions absolutely knock it out of the park. Every one of these, from the Ford Model T all the way down to the mustang at the end show such an enormous degree of patience and care, and it definitely matches up with the time estimates you jotted down on each page.

When it comes to these last handful of constructions, I unfortunately don't really have any critique to offer. While I'm sure there are little mistakes here and there, in the context of this course they simply do not matter. What matters is that you've demonstrated an exceptionally well developed grasp of 3D space and spatial relationships, along with a number of other critical qualities - patience, discipline, and a willingness to put your nose to the grindstone and work until these assignments are completed.

It actually goes a bit further than that, too - in your last drawing, the mustang emerges as if from a forest of lines, where any one of those marks could have been off. In fact, I'm certain you must have made at least a handful of little blunders in working off the wrong grid mark here and there (not that I can find any at a glance). Either way, what I'm really talking about here is the sheer weight of doubt that would press down on anyone in such a situation would no doubt he an unfathomably difficult thing to face - and you did so for a solid 11.5 hours, having faith that the process would carry you through, and rolling with whatever punches came at you. You didn't just show patience and discipline here - you showed true stalwartness, and it's that which will have the greatest impact as you continue to move forwards to pursue whatever goals you aim to achieve.

I am truly proud of what you've accomplished here, and I hope you are too. While it may well have been hell, you have shown yourself to be a survivor. You will achieve whatever it is you strive for, whether it's in drawing, or whatever else. And with that, I'll go ahead and mark this lesson, and with it the entire course, as complete. Congratulations - you have most certainly earned it.