I use a different kind of plastic that I buy locally, but it's about the same as styrene.
This vehicle required a small amount of plastic. The front skis andsome small pieces I used to cover holes left when I removed other stuff. The tracks are made from a cast I did.
On this vehicle all of the bottom is made from sheet plastic. I actually heated the plastic and press mold parts for detail. The landing gears, covers, and all that is from the plastic I use. So this one gives an even better idea what can be done.
This HISS tank I made the back hatch from sheet plastic. I hand carved the details in with a dremel then heated and bent the plastic to shape. I sanded the edge where I bent it to get the sharp point. The hinge is made from plastic too. The guns are wood and the base of the guns are from a mold. There's a seat inside the turrent made from sheet plastic too.
I've got other stuff too but no images to point to. If you saw the recent info about the Cobra Base, that's also made from this plastic I use. I like this stuff I use better than styrene due to it's ability to carve, heat and mold, plus I can buy various thicknesses. But you can still do a lot with styrene as well, as has been shown by others. I'd say you're only limited by your imagination on what can be done.