im pretty sure thats just a split screen specific tachometer, since splitscreen ui is in the gamefiles of 0.39, but unused. and the tachometer looks very similar to that
You are correct: Though I'd imagine you could add it to normal singleplayer using the UI app configurator.
I'm pretty sure these details doesnt exist acually in 0.38 (especially for moonhawk antenna) Otherwise, it sounds like Etk i6 (at 0:05) and Scintilla v8 (at 0:03) both received a brand new engine sound!
You’re probably right about the moonhawk antenna. That’s definitely new. The logo on the hopper has been there for a while IIRC. It’s on the park ranger config I believe