that's some amazing work, since matchbox cars are so small. nice use of nails on the Snake truck. You might want to look for Evergreen styrene to make building easier. (easier to cut and glue)
yes for some reason I just love working on the hot wheels size cars. I see you make larger models - your work is killer shown on your link there.
I had to laugh cause you have a lighter laying near one of your cars (maybe the Mack truck), and my cars are as small, or smaller than, the lighter. LOL
and yes I use Evergreen styrene all the time, for example the chassis all of the sheet "metal" on the Humungus car is styrene - I used greenstuff for the central part behind the engine, and some other garage found junk for parts, like the front fenders are picture hangers that I bent to shape.
I enjoy improvising parts from my junk drawer, etc. it's fun talking to other modelers to see what they are using, I've learned SO MUCH that way. in many ways I owe my progress to a couple guys who were really helpful when I reached out with questions, having seen how much better their work was from mine, some years ago.