Yes, I sanded the parts as much as I could, I also separated some parts to make it easier to sand some areas where otherwise it would be difficult to get into a corner. The engine parts mostly aren’t sanded since that would remove details. For the body I also used plastic polish after painting to get it even smoother.
For the windshield it was printed in clear material, when it comes out it has a frosted look because the part is made of stepped layers, so I had to carefully sand that to make it clear again as much as possible, took probably 3 hours of sanding from 240 grit to 20,000 grit. I also used mineral oil to help it a bit more.